Evaluating Citrus Rootstock Tolerance to Osmotic Stress Induced by PEG in Vitro

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Abdel-Aziz, Abd El-wahed N. Abd El-wahed, Ibrahim A. Elnaggar, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8428516/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract Citrus is one of the most widely planted fruit crops in the world, yet its growth and productivity are extremely susceptible to abiotic stresses, especially salinity and drought. With increasing climate change, water scarcity is becoming a major challenge, making the development of drought-tolerant rootstocks an important target in citrus biotechnology. The tolerance responses of four citrus rootstocks Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange under osmotic stress caused by polyethylene glycol (PEG) were assessed in this study. To replicate drought conditions, PEG-6000 shock treatments at doses of 0%, 4%, and 8% were applied to in vitro cells cultivated in 2024. Antioxidant enzyme activity, molecular characteristics, biochemical reactions (chlorophyll a, chlorophyll b, carotenoids, and relative water content), and morphological parameters (shoot number, shoot length, and leaf number) were all noted. PEG stress significantly reduced all growth and photosynthetic traits, while proline accumulation and antioxidant enzyme activity increased compared with the control, indicating activation of stress defense mechanisms. Genetic analysis using protein electrophoresis and peroxidase isozymes revealed banding pattern variations among rootstocks and treatments, demonstrating the usefulness of these biochemical markers in detecting genetic diversity under stress. Based on the combined results, Cleopatra mandarin showed the highest drought tolerance, followed by Citrus macrophylla, Volkameriana lemon, and Trifoliate orange. These findings suggest that the evaluated characteristics are effective for screening drought tolerance in citrus. The study highlights the potential of drought-tolerant rootstocks, particularly Cleopatra mandarin, for improving citrus adaptation and productivity under future water-limited environmental conditions. protein electrophoresis photosynthetic pigments isozyme markers enzyme activity scot-pcr Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction Citrus is one of the most important fruit crops worldwide; however, its productivity is seriously limited due to abiotic stresses, especially drought, which is worsening under climate change and increasing water shortage in arid and semi-arid areas [ 1 ]. Egypt occupies one of the advanced positions in the world ranking of citrus fruit production, with more than 4 million tons produced every year, which makes the breeding of drought-tolerant cultivars and rootstocks a highly actual task of agriculture[ 2 ]. Rootstock selection has the critical role of improving drought tolerance in grafted citrus by the modulation of water relations, osmotic adjustment, and stress signaling. In vitro screening using polyethylene glycol (PEG) offers a controlled and reproducible system to simulate osmotic stress, enabling rapid evaluation of rootstock responses without confounding environmental variables. Under drought conditions, plants trigger several physiological and biochemical defense mechanisms, including the accumulation of Osmo protectants such as proline, changes in photosynthetic pigment content, and increased antioxidant enzyme activity. Molecular markers are highly effective in the estimation of genetic diversity and identification of stress-responsive traits. SSR and SNP markers, though widely used, often lack direct functional association with phenotypic traits [ 3 ]. In contrast, functional markers like the Start Codon Targeted Polymorphism (SCoT) target gene-rich regions near start codons, offering higher reproducibility and closer linkage to adaptive traits[ 4 ]. SCoT markers have been applied to genotype discrimination and screening for stress tolerance in a wide range of crops such as tomato and citrus[ 5 ];[ 6 ]. Despite the availability of multiple citrus rootstocks, there are limited comparative studies integrating morphological, physiological, biochemical, and molecular analyses under PEG-simulated drought stress. Investigations on the correlations between drought tolerance, proline-related gene expression, antioxidant enzyme profiles, and SCoT-based genetic diversity in citrus rootstocks remain scarce. Therefore, the objective of this work was to: Study the drought tolerance of the four citrus rootstocks Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange under in vitro PEG-induced osmotic stress. Investigate morphological, photosynthetic, and physiological responses including proline accumulation and relative water content. Study the antioxidant enzyme activity such as POD and SOD and protein profiles under stress conditions. Genetic diversity and stress-associated molecular patterns would be investigated using SCoT markers and detection of some proline-related genes. We hypothesized those superior rootstocks for drought tolerance would show better maintenance of growth and higher photosynthetic pigment stability, enhanced proline accumulation, and different molecular and biochemical marker profiles. These results are expected to contribute further to the selection and breeding of the most appropriate drought-tolerant citrus rootstock for sustainable production under conditions of limited water supply. 2. Materials and methods 2.1. Plant material In the years 2023 and 2024, the tests were conducted in the tissue culture lab of the Horticulture Department, Faculty of Agriculture, Al-Azhar University, Nasr City, Cairo, Egypt. 2.1.2. Disinfection of explant Fruits were collected from twelve-year-old trees of four citrus rootstocks: Cleopatra mandarin ( Citrus reshni Hort. ex Tanaka), trifoliate orange ( Poncirus trifoliata L. Raf.), Volkameriana lemon ( Citrus volkameriana Tan.), and macrophylla ( Citrus macrophylla Wester). Seeds of all rootstocks were harvested from mother trees maintained in the germplasm collection of the Agricultural Research Center (ARC), Giza, Egypt (30°30′1.4″ N, 30°19′10.9″ E). The fruits were submerged in 99.6% ethanol for 15 minutes after being carefully cleaned under running water for 30 minutes to get rid of any surface debris. Following this, the fruits were briefly flame-sterilized for 5 seconds under laminar airflow conditions. Seeds were carefully extracted from the fruits on sterilized paper within the laminar flow hood. After that, the seeds were ready for in vitro cultivation in Murashige and Skoog (MS) medium devoid of plant growth regulators. Drops of 0.1 N potassium hydroxide (KOH) or hydrochloric acid (HCl) were added as needed to bring the medium's pH down to 5.7. Transparent polypropylene lids were placed over sterile 100-mL glass jars that held 25 mL of medium apiece[ 7 ]. The media-filled jars were autoclaved under 1.5 kg/cm² pressure for 20 minutes at 121°C. Prior to seed inoculation, the jars were allowed to cool to room temperature and kept tilted in the culture cabinet until needed. Cool white, fluorescent lamps with an intensity of 3000 lux were used to give 16-hour photoperiods while the cultures were cultured at 27°C for four weeks. To guarantee uniformity, each treatment was repeated three times. 2.1.2. Cultivation and Shoot Proliferation of Citrus Rootstocks: Explants were cultivated on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L BA and 0.01 mg/L NAA using shoot tips or micro-cuttings from all evaluated citrus rootstocks [ 8 ]. The seeds that germinated as previously mentioned produced these explants. Cool white, fluorescent lights with an intensity of 3000 lux were used to give a 16-hour photoperiod while the cultures were kept at 27°C for four weeks. To guarantee the trustworthiness of the experiment, each treatment was repeated three times. 2.1.3. In Vitro Mass Multiplication of Citrus Rootstocks Murashige and Skoog (MS) basal medium (1962) supplemented with 30 g/L sucrose, 1.0 mg/L BA (6-Benzylaminopurine), and 1.0 mg/L KIN (kinetin) were used to transfer axillary shoots from the various citrus rootstocks[ 9 ]. For four weeks, cultures were kept in a growth chamber at 27°C with a 16-hour photoperiod supplied by cool white, fluorescent lights with an intensity of 3000 lux. To guarantee effective mass propagation of all evaluated rootstocks, each treatment was repeated three times. 2.1.4. Induction of Abiotic Stress The purpose of this study was to evaluate how citrus rootstocks Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and macrophylla responded to increasing drought stress in vitro. After being moved from the multiplication medium to MS media with 30 g/L sucrose, 1.0 mg/L BA, and 0.01 mg/L NAA, uniform explants were subjected to 0.0%, 4%, and 8% polyethylene glycol (PEG). Three plantlets were used in each of the three replicates of each treatment. 2.2. Data Collection: Morphological and Biochemical Traits 2.2.1. Assessment of Morphological Characteristics The number of freshly formed shoots, shoot length (cm), and total number of leaves per shoot were measured to assess axillary shoot growth under drought stress after 30 days of culture. The vegetative response of each citrus rootstock to increasing PEG-induced drought stress was summarized by these metrics. 2.2.2. Photosynthetic Pigment Determination Following the Lichtenthaler and Buschmann [ 10 ] approach, the amounts of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the leaves were measured at the conclusion of the experiment (after 30 days). After being pulverized in a mortar with 15 mL of 80% acetone, around 0.2 g of fresh leaf tissue was filtered. The absorbance of the extract was determined using a UV-Vis spectrophotometer (Jenway, Model 715) at wavelengths of 470, 663, and 646 nm. 80% acetone was used as a blank for instrument calibration. The following formulas were used to determine pigment concentrations: $$\:Chloroplly\:a=12.25\:\times\:A663.2-2.79\times\:A646.8\:$$ $$\:Chloroplly\:b=21.21\:\times\:A646.8-5.1\times\:A666.2$$ $$\:Carotenoids=1981000\:\times\:A470-1.8\times\:Chl\:a-85.02\times\:Chl\:b$$ Chl b, where Chl a, Chl b, total chlorophyll, and Car represent the concentrations of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids, respectively. All pigment contents were expressed on a fresh weight basis. 2.2.3. Proline Content Analysis Proline levels were determined using the colorimetric method of Bates et al. [ 11 ]. After homogenizing fresh leaf tissue in 3% aqueous sulfosalicylic acid, it was filtered. After reacting to two milliliters of the filtrate with two milliliters of acid-ninhydrin and two milliliters of glacial acetic acid at 100°C for an hour, the mixture was chilled in an ice bath. Four milliliters of toluene were used to extract the reaction product, and toluene was used as a blank to measure absorbance at 520 nm. A standard curve was used to determine the proline concentration based on fresh weight. [(,ag proline/ml × ml toluene) / 115.5 ixg/lzmole]/[(g sample)/5] -= ~moles proline/g of material with fresh weight. 2.2.4. Leaf Relative Water Content (RWC) In accordance with (Garcı́a-Mata and Lamattina [ 12 ], the effect of PEG on leaf RWC in four citrus rootstocks was evaluated. In each replication, two leaves were chosen at random from the central section of each plant. After measuring the fresh weight (FW), the leaves were submerged in distilled water at 22°C for a full day to estimate the turgid weight (TW). To determine dry weight (DW), leaves were oven-dried for 48 hours at 80°C. $$\:Relative\:water\:content\:\left(\%\right)=\frac{Fresh\:weight-dry\:weight}{turgid\:weight-dry\:weight}\times\:100$$ 2.2.5. Genetic Analysis SCoT-PCR Analysis SCoT-PCR amplification was carried out using the(Collard and Mackill 2009) methodology. The four citrus samples were characterized using five SCoT primers: SCoT-1 (CAACAATGGCTACCACCA), SCoT-3 (CAACAATGGCTACCACCG), SCoT-4 (CAACAATGGCTACCACCT), SCoT-10 (CAACAATGGCTACCAGCC), and SCoT-13 (ACGACATGGCGACCATCG). 10 µL sterile water, 10 µL master mix, 2.5 µL primer, and 2.5 µL genomic DNA made up the PCR reaction mixture (25 µL total volume).An initial denaturation at 94°C for three minutes, 35 cycles of 94°C for one minute, 50°C for one minute, and 72°C for ninety seconds, and a final extension at 72°C for seven minutes comprised the thermal cycling conditions. A Gel Documentation System was used to visualize the separated PCR results on 1.5% agarose gels. 2.2.6. Detection of Proline-Related Genes DNA Extraction and PCR Amplification Following the manufacturer's recommendations, fresh young leaf tissues from the four citrus rootstocks (M, V, C, and P) were used to extract genomic DNA using the QIAGEN BioSprint Plant DNA Kit. Before being used again, extracted DNA was kept at -20°C.The SbP5CS1 gene's promoter region was amplified using primers P1-F (5′-TTGCTGATCCCTTGCTGC-3′) and P1-R (5′-ATCCCTCCTCTCCCCATT-3′). A total of 25 µL was used for PCR reactions, which included 10 µL of sterile water, 10 µL of master mix, 2.5 µL of primer, and 2.5 µL of genomic DNA. The thermal cycling schedule included a 5-minute initial denaturation at 94°C, 35 cycles of 94°C for 30 seconds, 55°C for 30 seconds, and 72°C for 2.5 minutes, and a final 10-minute extension at 72°C. Statistical and Molecular Data Analysis A fully randomized block design was used to set up the experiment. Two-way ANOVA in Co-Stat software (Stern, 1991) was used for analysis of variance (ANOVA), and Duncan's multiple range test was used to compare means at a significance level of p < 0.05. To reduce errors, distinct and well-resolved bands were visually assessed for molecular data. Bands were scored as present (1) or absent (0) to create a binary data matrix. The number of polymorphic bands divided by the total number of bands for each primer yielded the percentage of polymorphism. Jaccard's coefficient was used to determine the genetic similarity of the samples[ 13 ]. To assess the general genetic linkages, principal component analysis (PCA) was then carried out using the D-Center module Abouseadaa et al. [ 14 ]. 3. Results 3.1. Evaluation of Growth characteristics Table 1 illustrates the effects of PEG treatments on the morphological characteristics of the four evaluated citrus rootstocks. In comparison to the control, the results indisputably revealed that when the PEG concentration climbed from 4% to 8% under direct (shock) treatment, the number of shoots, shoot length (cm), and leaf number reduced. However, when exposed to higher levels of water deficiency stress caused by increasing PEG concentrations from 4% to 8%, all investigated rootstocks experienced a drop in growth rate. When compared to the other rootstocks, trifoliate orange rootstocks exhibited the highest values for these morphological characteristics, suggesting a significant variation in the rootstocks' reactions to PEG treatments at both concentrations. Raising the polyethylene glycol (PEG) concentration from 4% to 8% resulted in a significant decrease in shoot number, shoot length, and leaf number across all evaluated citrus rootstocks subjected to direct (shock) treatment, along with an increase in mortality rates, according to the results shown in Table 1 . Table 1 Shows how certain citrus rootstocks cultivated in vitro were affected morphologically by drought stress using PEG Rootstocks Treatments Concentration (%) Shoot number Shoot length (CM) Leaves number Cleopatra mandarin Control 0.0 6.33ab 7.00a 7.33a PEG 4.0 4.33cde 5.20cd 5.33bc PEG 8.0 4.00cde 3.20f 4.67bcd Trifoliate orange Control 0.0 6.67a 6.50ab 7.67a PEG 4.0 5.33bc 5.80bc 5.67bc PEG 8.0 4.33cde 3.90ef 5.33bc Volkameriana lemon Control 0.0 5.33bc 5.53bc 6.33ab PEG 4.0 3.67de 4.83cde 4.67bcd PEG 8.0 3.67de 3.07f 3.67de Citrus macrophylla Control 0.0 5.00cd 4.33de 5.67bc PEG 4.0 4.33cde 3.33f 4.00cde PEG 8.0 3.00e 2.10g 3.00e LSD at 5%: Treatments(T) = 0.59 0.46 0.85 LSD at 5%: Rootstock(R)= 0.68 0.53 0.74 LSD at 5%: (Treatments x Rootstocks) = 1.19 0.93 1.48 Cleopatra mandarin Duncan’s Ab A a Trifoliate orange A A a Volkameriana lemon Bc B b Citrus macrophylla C C b Control A A a PEG (4%) B B b PEG (8%) C C c 3.2. Photosynthesis pigment evaluation Table 2 summarizes the effects of PEG-induced drought stress (direct shock treatment) on photosynthetic pigments, including total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids. All citrus rootstocks subjected to 4% and 8% PEG showed a marked decrease in pigment content when compared to the control. The magnitude of reduction was concentration-dependent, with 8% PEG causing the greatest decline. Among the rootstocks, trifoliate orange maintained the highest pigment levels, followed by Cleopatra mandarin, Volkameriana lemon, and Citrus macrophylla, highlighting genotype-specific tolerance to osmotic stress. Table 2 Effect of drought stress using PEG on photosynthesis pigments of some citrus rootstocks grown in vitro. Rootstocks Treatments Concentration (%) Chlorophyll a /100g.F. W Chlorophyll b /100g.F. W Chlorophyll total/100g.F. W Carotenoids/100g.F. W Cleopatra mandarin Control 0.0 17.19a 18.07ab 18.69ab 4.50b PEG 4.0 13.52bcd 14.32c 15.71de 4.07c PEG 8.0 8.26ef 8.67de 12.58gh 3.03e Trifoliate orange Control 0.0 18.18a 19.10a 19.65a 5.53a PEG 4.0 14.82b 15.05c 16.88cd 4.80b PEG 8.0 9.38e 9.73d 13.08fg 3.86cd Volkameriana lemon Control 0.0 16.85a 17.40b 17.89bc 3.80cd PEG 4.0 13.31cd 13.66c 15.21e 3.60d PEG 8.0 8.00ef 8.25e 12.10gh 2.77e Citrus macrophylla Control 0.0 14.18bc 14.62c 17.10cd 2.80e PEG 4.0 12.31d 13.85c 14.42ef 2.68e PEG 8.0 7.33f 7.81e 11.31h 2.21f LSD at 5%: Treatments(T) = 0.67 0.66 0.72 0.17 LSD at 5%: Rootstock(R)= 0.77 0.76 0.83 0.19 LSD at 5%: (Treatments x Rootstocks) = 1.34 1.32 1.44 0.34 Cleopatra mandarin Duncan’s b B b b Trifoliate orange a A a a Volkameriana lemon b B bc c Citrus macrophylla c C c d Control a A a a PEG (4%) b B b b PEG (8%) c C c c 3.3. Evaluation of Biochemical and Physiological Characteristics 3.3.1. Proline Content The effect of PEG-induced drought stress (4% and 8%) on leaf proline content in four citrus rootstocks is presented in Table 4 . Increasing PEG concentrations led to a marked accumulation of proline in all rootstocks compared to the control. The highest proline levels were observed under 8% PEG, followed by 4% PEG, while the lowest values were recorded in the non-stressed control. Significant differences were found between the rootstocks, with Cleopatra mandarin having the highest proline accumulation, followed by Volkameriana lemon, Citrus macrophylla, and trifoliate orange, demonstrating genotype-specific osmotic stress responses. These results demonstrate how different the citrus rootstocks' reactions to drought stress are, with Cleopatra demonstrating the highest capacity to collect proline in stressful situations. According to the findings, there were notable genotypic differences between the rootstocks (Cleopatra > Trifoliate > Citrus macrophylla > Volkameriana lemon) and a notable increase in leaf proline content across all assessed citrus rootstocks when the concentration of polyethylene glycol (PEG) was raised from 4% to 8%. The highest accumulation was observed under 8% PEG. Plants have a well-established adaptive response to water scarcity or osmotic stress: proline buildup. It serves as a suitable osmolyte, stabilizes proteins and membranes, and scavenges reactive oxygen species (ROS). 3.3.2. Leaf relative water content (LRWC) Table 3 shows the effects of PEG-induced drought stress (direct shock treatment) on leaf relative water content (LRWC) in the citrus rootstocks tested. All rootstocks grown on MS medium supplemented with 4% or 8% PEG had lower LRWC than the control. Among the rootstocks, Volkameriana lemon had the greatest decrease in LRWC under 8% PEG, while Cleopatra mandarin had the highest, followed by trifoliate orange. These findings show significant genotype-dependent variation, with LRWC decreasing steadily as PEG concentration climbed from 4% to 8%. This suggests that PEG-induced osmotic stress successfully decreased the amount of water present in plant tissues, resulting in dryness of the cells. A concentration-dependent link between the level of water stress and leaf water status was demonstrated by the more noticeable decrease in RWC at 8% PEG. Table 3 Effect of drought stress using PEG on biochemical and physiological characteristics of some citrus rootstocks grown in vitro Rootstocks Treatments Concentration (%) Proline π/g F. W RWC % Cleopatra mandarin Control 0.0 1.17f 96.36a PEG 4.0 1.60de 81.45bc PEG 8.0 1.96b 64.08d Trifoliate orange Control 0.0 1.40e 97.47a PEG 4.0 1.80bc 85.83b PEG 8.0 2.40a 68.69d Volkameriana lemon Control 0.0 1.03f 95.10a PEG 4.0 1.40e 78.51c PEG 8.0 1.70cd 54.91e Citrus macrophylla Control 0.0 0.84g 93.17a PEG 4.0 1.20f 68.51d PEG 8.0 1.50e 48.24f LSD at 5%: Treatments(T) = 0.09 2.71 LSD at 5%: Rootstock(R)= 0.10 3.13 LSD at 5%: (Treatments x Rootstocks) = 0.18 5.43 Cleopatra mandarin Duncan’s B b Trifoliate orange A a Volkameriana lemon C c Citrus macrophylla D d Control C a PEG (4%) B b PEG (8%) A c 3.3.Genetic description 3.3.1. SCoT-PCR Analysis Five Start Codon-Targeted (SCoT) primers were used to evaluate the genetic similarity and polymorphism of the four citrus rootstocks—Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and Citrus macrophylla (Fig. 1 ). Each primer produced five to eleven amplified fragments; SCOT-4 produced the most bands, while SCOT-10 and SCOT-13 produced the fewest. The degree of intra-genotypic variation within each rootstock was significantly lower than the inter-genotypic variance among the cultivars evaluated, despite the presence of polymorphic bands. Five Start Codon Targeted (SCoT) primers were used to assess the genetic similarity and polymorphism of the four citrus rootstocks: Cleopatra mandarin, Trifoliate orange, Volkameriana lemon, and Citrus macrophylla (Fig. 1 ). Five to eleven fragments were amplified by each primer; SCot-4 produced the most bands, while SCot-10 and SCot-13 produced the fewest. The amplification products were between 111.9 and 1840.1 bps in size of the 37 scoreable fragments, 28 were polymorphic among the accessions, and 9 were monomorphic, according to Table 4 , which shows that all the tested primers produced polymorphic bands. The number of polymorphic bands ranged from three to ten, and the average polymorphism/primer was 5.6. The percentage of polymorphism revealed by the different primers ranged from 50.0 to 90.9%, with an average of 72.18 percent. Amplification results from the SCoT-PCR analysis of the four citrus rootstocks ranged from 111.9 to 1840.1 bp, suggesting that the primers chosen to target a wide range of genomic regions, from tiny to sizable fragments. Table 4 Using five primers, SCoT markers identified genetic variation in four citrus rootstocks Primer Size of fragments (bP) Total number of bands Monomorphic bands Polymorphic bands Polymorphism % SCoT 1 209.6–1584.0 10 2 8 80.0% SCoT 3 111.9–569.9 6 3 3 50.0% SCoT 4 294.4–1772.9 11 1 10 90.9% SCoT 10 389.8–1840.1 5 2 3 60.0% SCoT 13 762.3–1637.0 5 1 4 80.0% Total ---- 37 9 28 ----- Average ---- 7.4 1.8 5.6 72.18% The genetic similarity of the four citrus rootstock genotypes in the dendrogram ranged from 0.128 to 0.961 (Table 5 ). Citrus macrophylla and trifoliate orange rootstocks had the highest genetic similarity (0.961) according to the biochemical and molecular genetics investigation, whereas citrus macrophylla and Cleopatra mandarin had the lowest similarity index (0.128). The significant degree of polymorphism detected by SCoT primers reflects the unique genetic organization of Cleopatra mandarin, Trifoliate orange, Volkameriana lemon, and Citrus macrophylla. Table 5 Genetic similarity relationships among four citrus rootstocks used for cluster analysis Cultivars Cleopatra mandarin Citrus macrophylla Volkameriana lemon Trifoliate orange Cleopatra mandarin 1.000 Citrus macrophylla 0.182 1.000 Volkameriana lemon 0.530 0.420 1.000 Trifoliate orange 0.892 0.961 0.703 1.000 3.3.2. Determined of Presence proline-related genes Proline-related genes were used to determine the genetic relationships between the four citrus rootstocks under investigation to assess their drought responsiveness. The findings showed that the primer (SbP5CS1) was associated with proline-related genes having a molecular weight of 485.19 kb in Table 6 and Fig. 2 . This suggests that while the Citrus macrophylla rootstock lacks antioxidant genes, the cultivars (Cleopatra mandarin, trifoliate orange, and Volkameriana lemon) do. The primer SbP5CS1, which amplified a 485.19 bp fragment, was used to assess the presence of genes linked to proline. The findings show that the rootstocks of Cleopatra mandarin, trifoliate orange, and Volkameriana lemon contain the proline biosynthesis gene associated with SbP5CS1. In contrast, Citrus macrophylla did not show amplification, indicating that this gene is either absent or expressed at a very low level under the conditions tested. The findings show that the rootstocks of Cleopatra mandarin, trifoliate orange, and Volkameriana lemon contain the proline biosynthesis gene associated with SbP5CS1. In contrast, Citrus macrophylla did not show amplification, indicating that this gene is either absent or expressed at a very low level under the conditions tested. 3.4. Biochemical genetic identification of Citrus rootstocks 3.4.1. Antioxidant enzyme activities 3.4.1.1. Peroxidase (POD) The results of the electrophoresis of peroxidase in (Table 7 and Fig. 3 ) showed that it can be relied upon to identify between the rootstocks and the treatments within a given item. Where it was clear, there were 2 bands with monomorphic at Rf 0.182, and 0.688. While there were 3 unique bands as Rf 0.614 characterized Citrus macrophylla, Rf 0.760 marked Volkameriana lemon, while the third at Rf 0.775 identified Cleopatra mandarin. Without the rest of the rootstock and the treatments inside. When we look at the results of the electrophoresis between the rootstocks and the treatments within the item, we find characteristic bands, identify Citrus macrophylla and treatments for the same item, we find 2 bands at Rf 0.591 and 0.729, which are found in treatments and aren’t found in the rootstock. These areas are thought to be distinctive bands of treatments and could be caused by the expression of drought-resistant genes in the rootstocks or by the action of oxidation enzymes within the cells. In the high content drought treatment, rootstock Cleopatra mandarin displayed a band at Rf 0.731; it was absent in the rootstock and other treatments. Finally, rootstock trifoliate orange that was different from the three rootstocks. The results showed that there were unique bands at Rf 0.731 in the rootstock trifoliate orange. While the results showed that 2 bands appeared in drought coefficients without origin at Rf 0.729, 0.774 and that these locations may be due to the activation of drought genes within cells. Peroxidase (POD) enzyme electrophoresis revealed distinct banding patterns among the four citrus rootstocks and across drought treatments, indicating that POD activity can serve as a biochemical marker for genotype differentiation and stress response. Two monomorphic bands at Rf 0.182 and 0.688 were observed across all cultivars, suggesting conserved POD isoforms that are constitutively expressed irrespective of genotype or stress conditions. Distinct polymorphic bands were detected among the rootstocks, with unique bands at Rf 0.614, 0.760, and 0.775 corresponding to Volkameriana lemon, Trifoliate orange, and Cleopatra mandarin, respectively. Table 7 Isomers of Peroxidase (+/-) and their Rf value Band No. Rf M1 M3 M5 V1 V3 V5 C1 C3 C5 P1 P3 P5 Frequency Polymorphism Plus/Minus data for (Peroxidase) gel image 1 0.182 + + + + + + + + + + + + 1.000 Monomorphic 2 0.591 - + + + - - - - - + + + 0.500 Polymorphic 3 0.614 + - - - - - - - - - - - 0.083 Unique 4 0.648 + + + + + + + + - + + + 0.917 Polymorphic 5 0.688 + + + + + + + + + + + + 1.000 Monomorphic 6 0.729 - + + - - - + + - - + + 0.500 Polymorphic 7 0.731 - - - - - - - - + + - - 0.167 Polymorphic 8 0.760 - - - + - - - - - - - - 0.083 Unique 9 0.774 - - - - - - - - - - + + 0.167 Polymorphic 10 0.776 - - - - - - + - - - - - 0.083 Unique Total bands 4 5 5 5 3 3 5 4 3 5 6 6 Polymorphis% 80% (Rf) = Relative mobility, (+) = Present, (-) = absent, (1) = control, (3, 5) = treatments 3.4.1.2. Superoxide dismutase (SOD) A polymorphism percentage of 50% is obtained from the results shown in (Table 8) which show the presence of two bands overall: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632. Overall, no distinct bands or significant variations between the cultivars and treatments were found by electrophoretic analysis of SOD. A polymorphism percentage of 50% is obtained from the results shown in Table 8 and Fig. 4 , which show the presence of two bands overall: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632. Overall, electrophoretic analysis of SOD across the cultivars and treatments revealed no unique bands or notable differences among them. The four citrus rootstocks showed two bands on superoxide dismutase (SOD) electrophoresis: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632, resulting in a 50% overall polymorphism. Unlike peroxidase (POD), the SOD banding pattern showed limited differentiation among cultivars and treatments, with no unique bands attributable to either genotype or stress condition. The predominance of a monomorphic band suggests that a constitutive SOD isoform is conserved across all citrus rootstocks, providing a basal level of ROS scavenging to mitigate oxidative stress. Table 8. Isomers of Superoxide dismutase (+/-) and their Rf value Band No. RF M1 M3 M5 V1 V3 V5 C1 C3 C5 P1 P3 P5 Frequency Polymorphism Plus/Minus data for (SOD) gel image. 1 0.632 + + + + + + + + + + + + 1.000 Monomorphic 2 0.804 - + + + + - + + + + + + 0.833 Polymorphic Total bands 1 2 2 2 2 1 2 2 2 2 2 2 Polymorphism % 50% (Rf) = Relative mobility, (+) = Present, (-) = absent, (1) = control, (3, 5) = treatments 3.5. Protein electrophoresis 3.5.1. SDS-PAGE protein banding patterns of citrus leaves Figure 4 displays the SDS-PAGE analysis of the four citrus rootstocks. The molecular weights of the 17 protein bands that were found ranged from 11.838 kDa to 83.745 kDa. Cleopatra mandarin has the fewest bands (8), while Volkameriana lemon had the most (15). Table 9 summarizes the bands' existence and absence, which were noted as (+) and (−), respectively. Eleven of the bands were polymorphic and six were monomorphic, making up a polymorphism percentage of 64.7%. Except for one band found only in trifoliate orange under the testing conditions, no distinct bands were seen in any of the rootstocks. No unique bands were observed across the rootstocks, except for a single band detected exclusively in trifoliate orange under the tested conditions. Analysis of band presence and absence indicated that six bands were monomorphic, present in all rootstocks, reflecting conserved proteins likely involved in basic cellular functions. In contrast, eleven bands were polymorphic, resulting in an overall polymorphism of 64.7%, which demonstrates substantial protein-level variability among the genotypes. No unique bands were observed among the examined rootstocks, except for one unique band detected in trifoliate orange rootstock under specific treatments, suggesting that most protein differences are quantitative or shared among genotypes rather than strictly qualitative. Table 9 Data matrix indicating the presence or lack of bands in leaf protein electrophoretic banding patterns for the four citrus rootstocks Band No. MW M1 M3 M5 V1 V3 V5 C1 C3 C5 P1 P3 P5 Frequency Polymorphism Plus/Minus data for (SDS-PAGE) protein gel image 1 83.745 - - - - - - - - - + - + 0.167 Polymorphic 2 80.554 - - - - - - - - - + + + 0.250 Polymorphic 3 65.964 + + + + - + - + - + + + 0.750 Polymorphic 4 60.863 + + - + + + + - - + + + 0.750 Polymorphic 5 56.313 + + + + + + + - + - + - 0.750 Polymorphic 6 49.840 + + + + - - - + - + - + 0.583 Polymorphic 7 47.412 + + + + + + + + + + + + 1.000 Monomorphic 8 45.102 - - - + - + - + - - + - 0.333 Polymorphic 9 42.196 + + + + + + + + + + + + 1.000 Monomorphic 10 40.140 + + + + + + - + + - + - 0.750 Polymorphic 11 36.122 + + + + + + + + + + + + 1.000 Monomorphic 12 33.053 + + + + - + - - - - - - 0.417 Polymorphic 13 19.346 - - + + + + - + - + + + 0.667 Polymorphic 14 17.314 + + + + + + + + + + + + 1.000 Monomorphic 15 16.747 + + + + + + + + + + + + 1.000 Monomorphic 16 15.668 - - - + + + - + - + - + 0.500 Polymorphic 17 11.838 + + + + + + + + + + + + 1.000 Monomorphic Total bands 12 12 12 15 11 14 8 12 8 13 13 13 Polymorphism (%) 64.706% Table 10 Correlation matrix showing the extent of Morphological, photosynthetic pigment, biochemical, and physiological characteristics in citrus rootstocks growing in vitro conditions Shoot number Shoot length c/cm Leaves number RWC % Chlorophyell a Chlorophyell B Total Chlorophyell Carotenoides Proline Shoot number 1 Shoot length c/cm 0.879** 1 Leaves number 0.951** 0.922** 1 RWC % 0.874** 0.910** 0.915** 1 Chlorophyell a 0.8764** 0.922** 0.871** 0.957** 1 Chlorophyell B 0.873** 0.903** 0.855** 0.940** 0.996** 1 Total Chlorophyell 0.917** 0.927** 0.913** 0.975** 0.989** 0.980** 1 Carotenoides 0.770** 0.873** 0.814** 0.686** 0.723** 0.705** 0.731** 1 Proline -0.330* -0.287* -0.249* -0.503** -0.567** -0.585** -0.545** 0.118* 1 Correlation is significant at the 5% level**; Correlation is significant at the 1% level * The parameters in Fig. 6 showed that shoot number, shoot length (cm), leaf number, RWC%, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and proline were biplotted to the different levels of drought stress caused by the PEG treatments (control, 4% PEG, and 8% PEG) using Principal Component Analysis (PCA). Approximately 93.8%, 91.5%, 96.6%, and 97.1% of the total variance was explained by the first principal component (PC1), whereas approximately 6.2%, 8.5%, 3.4%, and 2.9% were explained by the second principal component (PC2). Table 11 Principal component analysis contribution to eigenvalue, variance, and cumulative variance Macrophylla Cleopatra mandarin Poncirus trifoliata Volkamriana limon Principal component PC1 PC2 PC1 PC2 PC1 PC2 PC1 PC2 Eigenvalue 8.4 5. 5 8.2 7. 6 8.6 3. 2 8.7 2. 6 Variance 93. 8 6.2 91.5 8. 5 96.6 3.4 97. 1 2.9 Cumulative 93. 8 1.0 91. 5 1.0 96.6 1.0 97. 1 1.0 4.6. Correlation matrix and PCA The correlation study's findings demonstrated a robust paired relationship between the morphological, physiological, biochemical, and photosynthetic pigment characteristics of citrus rootstocks grown in vitro. The strength and direction of these relationships varied among the PEG-induced water stress treatments (0.0%, 4%, and 8%), which were associated with progressively increasing levels of drought stress. The physiological characteristics of chlorophyll concentration showed a highly significant and positive correlation with shoot number, shoot length (cm), leaf number, relative water content (RWC%), chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids across all PEG-induced water stress levels. On Proline, on the other hand, significantly altered the relationships between the morphological, physiological, and biochemical traits of citrus rootstocks by exhibiting a strong negative connection with most morphological and pigment-related indicators. PCA highlighted the first two components of 9 variables, where the first and second components were 93.8%, 91.5%, 96.6%, and 97.1% of the total variance, while the second principal component (PC2) explained around 6.2%, 8.5%, 3.4%, and 2.9%, as shown in Fig. 6 and Table 10 . Explants of drought stress brought on by the PEG treatments (control, 4% PEG, and 8% PEG) are mostly located at the upper right side of the plot and have a strong positive correlation with the first component: Shoot number, shoot length (cm), leaf number, RWC (%), chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids at the level of 4% PEG at the center of the plot, However, the explants that received 8% PEG treatment were primarily seen on the left side of the plot, indicating a significant rise in proline accumulation. These results indicate that 4% PEG-induced drought stress caused significant variation among the citrus rootstocks studied in their morphological, biochemical, and physiological characteristics. 4. Discussion These findings clearly indicate that PEG-induced osmotic stress has a detrimental effect on vegetative growth and highlights the susceptibility of citrus genotypes to water-deficit conditions. The observed reduction in morphological features is consistent with previous studies that found higher PEG concentrations reduce shoot elongation, leaf expansion, and total biomass accumulation due to decreased cell turgor and water uptake[15];[16]. The growth medium's osmotic potential, which PEG produces, limits the amount of water available and causes cellular dehydration, which prevents cell division and growth[17];[18]. According to the current study, this causes plants to have smaller leaves, shorter shoots, and less branching. According to (Ghosh et al., [19]; Memon et al., [20], the higher mortality rate at 8% PEG indicates that the applied osmotic stress surpassed the tolerance threshold of most tested rootstocks, resulting in irreversible cellular damage and loss of viability. The substantial variation in how different rootstocks react to PEG treatments emphasizes how crucial genetic background is in determining drought tolerance. Trifoliate orange showed the highest values for shoot number, shoot length, and leaf number under both stress levels in the current study, indicating a higher ability to respond to osmotic pressure and better growth maintenance in water-limited environments. Tolerant rootstocks exposed to PEG-induced stress maintained higher relative water content (RWC), membrane stability index (MSI), and chlorophyll fluorescence parameters, according to recent studies that reported similar genotype-dependent responses[21];[1]. These characteristics are frequently linked to effective osmotic adjustment mechanisms, such as increased root hydraulic conductance, improved antioxidant defense, and osmolyte accumulation (proline, soluble sugars)[22]. Furthermore, a highly developed and branching root system that promotes better water absorption and preserves cell turgidity even in the face of osmotic stress may be the cause of trifoliate orange's morphological robustness. In contrast to sensitive genotypes, tolerant rootstocks maintained more root tips, more root surface area, and longer total root length, according to high-throughput phenotyping of citrus genotypes under controlled drought circumstances[23]. Rather than promoting actual physiological tolerance, these traits help people escape drought better. Therefore, rather than using metabolic tolerance mechanisms, trifoliate oranges may predominantly use drought avoidance tactics through efficient water uptake and cautious water use. All things considered, the present findings are in line with earlier research that emphasizes the effectiveness of PEG treatments as a controlled and repeatable paradigm for determining the drought resilience of citrus genotypes[24];[25]. Field drought conditions cannot be accurately replicated by PEG-induced osmotic stress due to the lack of additional environmental factors like temperature fluctuations, soil texture, and microbial interactions[26]. Therefore, a more thorough evaluation of rootstock performance and durability will be possible by combining PEG-based laboratory screening with field assessments conducted under natural drought. The reduction in chlorophyll content under drought stress is typically caused by a variety of physiological and biochemical factors, including decreased chlorophyll biosynthesis, increased activity of enzymes that break down chlorophyll, such as chlorophyllase, and oxidative damage to chloroplast membranes caused by the accumulation of reactive oxygen species (ROS) [27];[28]. Limited water availability under PEG-induced water deficit decreases gas exchange and leaf turgor, which causes stomatal closure and a reduction in carbon fixation. This, in turn, slows down the generation of chlorophyll and speeds up the deterioration of pigments [29]. Comparably, under PEG stress, carotenoid content also dropped, but less sharply than chlorophyll levels. Because they dissipate excess electricity and quench singlet oxygen, carotenoids are essential for photoprotection [30]. The observed decline could be due to a general deterioration of the photosynthetic machinery and a decrease in antioxidant defense capabilities under severe osmotic stress. However, maintaining greater carotenoid levels is believed to be an essential adaptation strategy to reduce photooxidative damage during a water scarcity[31];[32]. Citrus rootstocks showed notable variations, suggesting genotype-dependent responses in pigment maintenance under osmotic stress. Under both PEG concentrations, trifoliate orange had the highest levels of carotenoid and chlorophyll, followed by Cleopatra mandarin, Volkameriana lemon, and Citrus macrophylla. This result suggests that Trifoliate orange has a greater capacity to preserve photosynthetic pigment integrity under drought stress. Similar genotype-specific differences have been documented, where tolerant rootstocks maintain higher pigment levels and photochemical efficiency (Fv/Fm) due to more effective antioxidant activity and osmotic adjustment[33]. Therefore, maintaining higher chlorophyll and carotenoid levels under PEG-induced drought can be considered a key indicator of drought tolerance in citrus. The ability of Trifoliate orange to retain these Thus, sustaining increased levels of carotenoid and chlorophyll under PEG-induced drought might be regarded as a crucial sign of citrus drought tolerance. Trifoliate orange's improved photosynthetic performance and growth stability under stress are probably influenced by its capacity to retain these pigments, which also supports its appropriateness as a rootstock in settings with low water. The highest accumulation was observed under 8% PEG. Plants have a well-established adaptive response to water scarcity or osmotic stress: proline buildup. It serves as a suitable osmolyte, stabilizes proteins and membranes, and scavenges reactive oxygen species (ROS). In citrus and other crops, studies conducted in the past ten years have confirmed that proline levels rise in response to osmotic, salt, or drought stress[34]. Differential proline buildup has been documented in citrus rootstocks. For instance, proline accumulation in leaves was utilized as a possible biochemical marker for water-stress resistance in sweet orange grafted combinations when there was a natural water scarcity in orchards[35]. Similarly, one of the biochemical responses associated with improved recovery following re-watering in a recent screening of nine citrus rootstocks under controlled drought stress was enhanced proline accumulation[36]. Our data's genotypic variance in proline accumulation points to a difference in the metabolic adaptation of rootstocks to osmotic stress. The Cleopatra rootstock's highest proline levels may suggest a robust osmotic adjustment system, which maintains cell turgor by collecting solutes to compensate for cellular water loss. On the other hand, more proline may not always indicate greater tolerance but rather a higher stress burden (more damage). In fact, according to some research, high proline can indicate the degree of stress rather than actual tolerance[37]. The dose-dependent pattern (higher PEG → higher proline) is consistent with recognized stress reactions. Higher osmotic pressure promotes the biosynthesis of proline by upregulating important enzymes like Δ¹-pyrroline-5-carboxylate synthetase (P5CS) and decreasing proline dehydrogenase (ProDH) activity. As a result, the proline findings support the hypothesis that biochemical osmotic adjustment plays an important role in citrus rootstocks' drought response to PEG-induced stress. They underline the need to use proline values as a screening parameter when evaluating rootstocks. Proline accumulation is most useful when combined with physiological (RWC, membrane stability), morphological (root/shoot properties), and pigment/photochemical data. As a result, the proline findings support the hypothesis that biochemical osmotic adjustment plays an important role in citrus rootstocks' drought response to PEG-induced stress. They underline the need to use proline values as a screening parameter when evaluating rootstocks. Proline accumulation is particularly valuable when combined with physiological (RWC, membrane stability), morphological (root/shoot properties), and pigment/photochemical data[38]. Several studies have reported that PEG treatments mimic water-deficit circumstances by reducing the culture medium's osmotic potential, which limits water absorption and reduces tissue hydration[21]. These outcomes are consistent with our findings. RWC is a well-known physiological indicator of plant water status because it shows the balance between water supply and transpiration losses. A decrease in RWC during PEG stress indicates reduced water intake and increased water loss due to lower root hydraulic conductivity and stomatal closure[16]. Differences in the citrus rootstocks' capacity to hold onto water under osmotic stress are highlighted by the diversity seen among them. Volkameriana lemon had the lowest RWC values, suggesting a higher vulnerability to dehydration, while Cleopatra Mandarin retained the greatest RWC values at both 4% and 8% PEG, followed by Trifoliate orange. Water retention capacity genotypic variability points to inherent physiological variations that may be associated with osmotic adjustment potential, cuticular or stomatal control, and root system design. Similar genotype-dependent alterations in RWC have been seen in citrus and related species under PEG or drought stress, with resistant rootstocks maintaining higher RWC and relative turgidity [39];[21]. Under osmotic stress, plants typically attempt to maintain turgor pressure by accumulating compatible solutes such proline and soluble sugars; nevertheless, RWC dramatically decreases when stress exceeds the plant's capacity to react to osmotic pressure[40]. This pattern is supported by the current study's findings, which show that RWC significantly decreased across all rootstocks at greater PEG concentrations. Better drought resistance is typically linked to maintaining higher RWC under osmotic stress or drought, as this permits ongoing photosynthesis, metabolic activity, and cell growth. Stronger antioxidant systems that lessen membrane damage, improved osmotic adjustment through solute buildup, and increased root hydraulic conductivity are all common characteristics of rootstocks that can sustain higher RWC[41];[42]. According to the current study, Cleopatra mandarin and trifoliate orange exhibit superior RWC maintenance, which may be a sign of more effective water conservation techniques. This could be due to structural characteristics that reduce water loss and osmotic adjustment, which is reflected in greater proline levels. On the other hand, Volkameriana lemons' significant RWC reduction indicates a restricted ability to regulate osmotically or minimize water loss, which leads to a larger loss of turgor during PEG stress. Volkameriana lemons have also been found in earlier studies to be very drought-sensitive, showing decreased RWC and membrane integrity under comparable stressors[43]. Therefore, the current results corroborate the idea that variations in RWC between citrus rootstocks under PEG-induced stress can be used as accurate physiological indicators to differentiate between genotypes that are tolerant and those that are sensitive. All things considered, the data show that RWC is a sensitive measure of water imbalance brought on by drought in citrus rootstocks and that it can successfully supplement morphological and biochemical (such as proline build up) evaluations in determining drought resistance. The better physiological robustness of Cleopatra mandarin and trifoliate orange, as well as their potential as viable rootstocks for citrus-growing locations that are prone to drought, is demonstrated by their capacity to retain higher RWC under osmotic stress. The idea that SCoT markers preferentially target functional regions close to the ATG start codon, which may harbor higher sequence variability, is supported by the variation in amplification that reflects variations in primer binding sites across the genomes of the tested rootstocks[6]. According to the research, inter-genotype variance was substantially more than intra-genotype polymorphism, which was comparatively modest. According to this pattern, the four rootstocks exhibit distinct divergence from one another while remaining genetically stable within themselves. Because it suggests the possibility of combining different genetic traits across rootstocks to improve stress tolerance, growth performance, or other desired horticultural traits, such interspecific variation is beneficial for breeding programs and germplasm conservation[5]. Given the greater number of polymorphic bands seen with SCot-4, it is likely that this primer targets more changeable genomic areas, such as coding sequences that affect stress-response pathways or gene expression. The complementing aspect of numerous SCoT primers in capturing total genetic variation is highlighted by the possibility that primers with fewer bands will amplify more conserved areas. All things considered, the findings show that SCoT markers are useful for identifying genetic variations between citrus rootstocks [6]. Their simplicity, dependability, and ability to target gene-rich regions make them a reliable approach for genotype identification, genetic diversity evaluation, and potential marker-assisted selection in citrus breeding programs[44]. Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange may all be clearly separated from one another at the molecular level, which offers important information for hybridization and rootstock selection tactics. This broad range of sizes is in line with earlier research that demonstrated that SCoT primers amplify areas surrounding the start codon, which can change significantly in length because of variations in coding sequences, untranslated regions, and introns[45]. The significant degree of polymorphism detected by SCoT primers reflects the unique genetic organization of Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and Citrus macrophylla. This type of polymorphism is highly helpful for breeding and conservation programs because it enables genotype discrimination, the identification of genetically different accessions, and the potential selection of rootstocks with superior traits[46]. This type of polymorphism is highly helpful for breeding and conservation programs because it enables genotype discrimination, the identification of genetically different accessions, and the potential selection of rootstocks with superior traits[47]. Additionally, the dendrogram offers light on how well molecular and biochemical tests match up. Given how similar Citrus macrophylla and Trifoliate orange are, it is possible that both rootstocks share physiological characteristics like proline accumulation or drought tolerance in addition to genetic regions. Both similarities might be used to select different rootstocks. On the other hand, Cleopatra mandarin's increased RWC and proline content under PEG-induced stress may be related to its genetic divergence, suggesting that rootstocks may have different functions[40]. As an osmoprotectant, ROS scavenger, and cellular structural stabilizer, proline accumulation is a known response to drought stress[48]. The greater proline levels seen in Cleopatra mandarin, trifoliate orange, and Volkameriana lemon under PEG-induced drought stress are consistent with the presence of proline-related genes in these cultivars. This link implies that these genotypes have an active proline biosynthesis pathway, likely mediated by Δ¹-pyrroline-5-carboxylate synthetase (P5CS), which contributes to their enhanced drought tolerance[40]. Citrus macrophylla lower proline accumulation and diminished ability to sustain cellular osmotic balance during drought stress may be attributable to the lack of SbP5CS1 amplification. Similar results have been reported for other citrus and horticulture species, where variations in drought tolerance among genotypes are correlated with the presence or expression of P5CS and other proline-related genes[27];[49]. The findings underscore the usefulness of molecular markers aimed at stress-responsive genes in assessing the genetic potential of rootstocks. Identifying functional genes associated with osmotic adjustment yields a mechanistic insight into genotype-specific drought responses and provides a molecular foundation for selecting rootstocks with enhanced stress resilience. The conclusion that Cleopatra mandarin, trifoliate orange, and Volkameriana lemon are better adapted to drought stress than Citrus macrophylla is reinforced by the combined analysis of physiological data (proline accumulation, RWC) and gene presence. These unique bands may reflect isoform-specific expression of POD enzymes linked to genetic variation among cultivars[50];[51]. Such cultivar-specific isoforms are useful for biochemical identification and indicate that the constitutive antioxidant capacity varies among rootstocks. When examining the impact of drought treatments, additional characteristic bands appeared that were absent from control plants. Bands at Rf 0.591 and 0.729 were detected across treatments but not in the rootstock controls, suggesting inducible POD isoforms activated under water deficit conditions. Similarly, at extreme PEG stress, cultivar-specific inducible bands were seen (Cleopatra mandarin at Rf 0.731), indicating the induction of POD isoforms in response to oxidative stress brought on by drought. These findings corroborate earlier research showing that drought stress increases the expression and activity of antioxidant enzymes, such as POD, which scavenge reactive oxygen species (ROS) and shield cellular components[52]. Interestingly, rootstock Trifoliate orange exhibited unique bands at Rf 0.731, while additional bands at Rf 0.729 and 0.774 appeared only under drought stress, suggesting both constitutive and inducible defense mechanisms. The observed physiological and biochemical reactions, such as proline buildup and maintenance of relative water content, are compatible with the activation of these isoforms, which most likely reflects the expression of drought-responsive genes encoding antioxidant enzymes. POD electrophoresis demonstrated both genotype-specific and stress-induced isoforms, highlighting the dual role of peroxidase as a molecular marker for cultivar identification and a functional marker for drought tolerance. Integrating these biochemical data with molecular markers (SCoT-PCR) and physiological traits provides a comprehensive approach for selecting citrus rootstocks with enhanced stress resilience. The presence of a single polymorphic band indicates minor variation among genotypes, but this variation was not sufficient to distinguish the rootstocks or drought treatments effectively. According to reports (Gill and Tuteja [53]; Wang et al. [42], inducible responses may be more subtle or post-translationally regulated, whereas SOD isoforms are frequently constitutively expressed in plants, acting as the first line of defense against superoxide radicals generated under stress. The absence of unique bands under drought stress implies that SOD activity in these citrus rootstocks may not vary significantly at the isoform level, and the stress response may instead be mediated by quantitative changes in enzyme activity rather than qualitative changes in isoforms. This contrasts with POD, which displayed clear cultivar-specific and stress-inducible isoforms, reflecting its more dynamic response to water deficit conditions. The absence of multiple unique bands indicates that drought-induced protein expression may not result in entirely novel polypeptides but rather in differential expression or accumulation of pre-existing proteins, which aligns with previous studies showing that abiotic stress often modulates protein abundance rather than creating new protein species[54]. The high polymorphism observed in the protein profiles highlights genetic and biochemical variability among citrus rootstocks, supporting their differentiation at the protein level. According to (Farooq et al. [55], proteins with molecular weights between 11 and 84 kDa may comprise antioxidant defense components, osmoprotective proteins, and stress-related enzymes that aid in drought tolerance. In line with the physiological and biochemical characteristics previously noted, such as increased RWC and antioxidant enzyme activity, the larger number of bands in Volkameriana lemon suggests a more complex protein response mechanism, possibly reflecting higher adaptive capacity under stress conditions. SDS-PAGE protein profiling complements molecular markers and physiological assays, providing an additional layer of evidence for the genetic and biochemical diversity among citrus rootstocks and their responses to drought stress. The identification of rootstocks with greater stress tolerance is further supported by the integration of these protein data with proline accumulation and antioxidant enzyme activity. 5. Conclusions In the current study, we have demonstrated the ability of in vitro PEG-induced osmotic stress to successfully assess drought tolerance among four citrus rootstocks: Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange. The integrated study of the morphological, physiological, biochemical, and molecular parameters expressed evident genotype-dependent responses to drought stress. PEG-induced water deficit significantly reduced the vegetative growth and photosynthetic pigment contents for all the tested rootstocks, with higher values recorded at 8% PEG. Cleopatra mandarin and trifoliate orange presented better drought tolerance through maintaining higher shoot growth, leaf number, and pigment stability than those in Volkameriana lemon and Citrus macrophylla. Physiological measurements indicated that the drought-tolerant rootstocks consistently had higher relative water content and a greater accumulation of proline under stress, demonstrating positive osmotic adjustment mechanisms. Molecular studies were done using SCoT markers, which indicated high genetic diversity among rootstocks, with the percentage of polymorphism exceeding 70%. Proline-related genes, such as SbP5CS1, were detected in Cleopatra mandarin, trifoliate orange, and Volkameriana lemon but not in Citrus macrophylla, thus correlating with the differences observed in proline accumulation and drought tolerance. Biochemical profiling showed that POD isoforms acted as an effective stress-responsive marker, which exhibited constitutive as well as inducible patterns under drought stress, while SOD was more conserved among genotypes. Cleopatra mandarin was found to be the most drought-tolerant, followed by trifoliate orange, Volkameriana lemon, and Citrus macrophylla. The strong correlations between morphological traits (shoot number, length), physiological parameters (RWC, pigments), and biochemical markers (proline, antioxidant enzymes) prove that this multi-level screening approach is effective. These findings support the use of PEG-induced osmotic stress as a reliable in vitro screening protocol for the assessment of drought tolerance in citrus rootstocks. By combining SCoT markers with physiological and biochemical analyses, a sound procedure is developed for identifying the genotypes resilient against drought conditions. Thus, Cleopatra mandarin has emerged as one of the more promising rootstocks for cultivation in water-scarce regions as well as in breeding programs seeking to enhance drought tolerance in citrus. Declarations Ethics approval and consent to participate The authors confirmed that the institutional committee and licensing committee approved the experiments, including all relevant details and that all experiments have been performed in accordance with specified named guidelines and regulations. Consent for publication: The article contains no such material that may be unlawful, defamatory, or which would, if published, in any way whatsoever, violate the terms and conditions as laid down in the agreement. Conflict of Interest The authors declare that the research was conducted in the absence of any commercial or financial and non-financial relationships that could be construed as a potential conflict of interest. Data Availability Statement The original contributions presented in the study are included in the 549 article; further inquiries can be directed to the corresponding author. Author Contributions Conceptualization, H.F.A. and A.E.H.; methodology, H.F.A.,A.E.H., A.N.A., I.A.E., M.E.A., A.E.A; software, A.E.H., A.A.S.; validation, A.E.H., A.N.A., and A.A.S.; formal analysis, A.E.H., H.F.A., I.A.E. and A.N.A.,; investigation, A.E.A; resources, A.E.H., I.A.E., and A.N.A.; writing—original draft preparation, H.F.A., A.E.H., I.A.E., A.E.A., and M.E.A. ; writing—review and editing H.F.A., A.E.H., M.H.F.M.H.F. and A.M.A.; visualization, A.N.A., I.A.E. and M.E.A.; supervision, A.E.H. ; project administration, A.M.A.; funding acquisition, A.M.A.; All authors have read and agreed to the published version of the manuscript. Funding This research was funded by Ongoing Research Funding Program (ORF-2026-334), King Saud University, Riyadh, Saudi Arabia. Acknowledgments The authors extend their appreciation to Ongoing Research Funding Program (ORF-2026-334), King Saud University, Riyadh, Saudi Arabia. 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Acquiring control: The evolution of ROS-Induced oxidative stress and redox signaling pathways in plant stress responses. Plant Physiol Biochem. 2019;141:353–69. https://doi.org/10.1016/j.plaphy.2019.04.039 . Additional Declarations No competing interests reported. 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Al-Saif","email":"","orcid":"","institution":"King Saud University","correspondingAuthor":false,"prefix":"","firstName":"Adel","middleName":"M.","lastName":"Al-Saif","suffix":""}],"badges":[],"createdAt":"2025-12-22 22:08:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8428516/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8428516/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102609286,"identity":"6c543d99-f675-4921-9c99-177adf91ffb3","added_by":"auto","created_at":"2026-02-13 14:36:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":270601,"visible":true,"origin":"","legend":"\u003cp\u003eDNA polymorphism analysis of four citrus genotypes using five SCoT primers. The lanes represent: C = Cleopatra mandarin, M = Citrus macrophylla, V = Volkameriana lemon, and P = Trifoliate orange, with (M) as the DNA ladder marker (bp).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/2627239d0e7e2ff1240fc9be.png"},{"id":102609287,"identity":"ca3f3ac9-9a7a-4171-8557-167d223d0638","added_by":"auto","created_at":"2026-02-13 14:36:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":114029,"visible":true,"origin":"","legend":"\u003cp\u003eDNA polymorphism of the four citrus genotypes leaves amplified with primer proline, (M) DNA ladder marker (bP), C = Cleopatra mandarin, M = Citrus macrophylla, V = Volkameriana lemon, and P = Trifoliate orange.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/6237673034dc78d60a7351ec.png"},{"id":102609288,"identity":"c89b7752-4d6d-4183-b11e-a8c45660c247","added_by":"auto","created_at":"2026-02-13 14:36:47","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":291506,"visible":true,"origin":"","legend":"\u003cp\u003eelectrophoresis of peroxidase of the four citrus genotypes leaves, C = Cleopatra mandarin, M = Citrus macrophylla, V = Volkameriana lemon, and P = Trifoliate orange and (3, 5) treatments\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/c3fc09a6eba9693b07ca25d0.png"},{"id":102609289,"identity":"dcfa4e51-8543-4f70-97fd-27bc57288bce","added_by":"auto","created_at":"2026-02-13 14:36:47","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":438908,"visible":true,"origin":"","legend":"\u003cp\u003eProtein electrophoresis of the four citrus genotypes leaves, (Mw) ladder protein, C = Cleopatra mandarin, M = Citrus macrophylla, V = Volkameriana lemon, and P = Trifoliate orange and (3, 5) treatments.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/46b812cf6107bf444033dcb0.png"},{"id":102609291,"identity":"2bd34ec4-d3c0-4cb8-bb73-738d485e47f5","added_by":"auto","created_at":"2026-02-13 14:36:47","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":396482,"visible":true,"origin":"","legend":"\u003cp\u003eA heat map of the correlation of the extent of morphological, photosynthetic pigment, biochemical, and physiological characteristics in citrus rootstocks growing in vitro, including shoot number, shoot length (cm), leaf number, RWC (%), chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and proline.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/08a53f9b18ec81f7a47d5d82.png"},{"id":102747949,"identity":"b2209bbd-31ef-4d82-a318-eab36aa7a4c6","added_by":"auto","created_at":"2026-02-16 09:05:38","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":152128,"visible":true,"origin":"","legend":"\u003cp\u003ePrinciple component analysis for biochemical and physiological characteristics effect of drought stress using PEG on morphological characteristics of some citrus rootstocks, A PCA-associated scatter plots associated with rootstocks and level of treatments.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/aa01c56e41676ac50de72100.png"},{"id":103056383,"identity":"342a5304-df44-4105-a991-2ee97a88cbc9","added_by":"auto","created_at":"2026-02-20 09:08:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4121958,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/59cf1f3b-be41-4bbe-989c-242b7dcf503c.pdf"},{"id":102747538,"identity":"fd391ec8-6da0-4c85-ab55-809e79b93f35","added_by":"auto","created_at":"2026-02-16 09:04:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":527755,"visible":true,"origin":"","legend":"","description":"","filename":"sublementry.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8428516/v1/f83de15f00048b3c184cb37f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Evaluating Citrus Rootstock Tolerance to Osmotic Stress Induced by PEG in Vitro","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eCitrus is one of the most important fruit crops worldwide; however, its productivity is seriously limited due to abiotic stresses, especially drought, which is worsening under climate change and increasing water shortage in arid and semi-arid areas [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Egypt occupies one of the advanced positions in the world ranking of citrus fruit production, with more than 4\u0026nbsp;million tons produced every year, which makes the breeding of drought-tolerant cultivars and rootstocks a highly actual task of agriculture[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRootstock selection has the critical role of improving drought tolerance in grafted citrus by the modulation of water relations, osmotic adjustment, and stress signaling. In vitro screening using polyethylene glycol (PEG) offers a controlled and reproducible system to simulate osmotic stress, enabling rapid evaluation of rootstock responses without confounding environmental variables. Under drought conditions, plants trigger several physiological and biochemical defense mechanisms, including the accumulation of Osmo protectants such as proline, changes in photosynthetic pigment content, and increased antioxidant enzyme activity.\u003c/p\u003e \u003cp\u003eMolecular markers are highly effective in the estimation of genetic diversity and identification of stress-responsive traits. SSR and SNP markers, though widely used, often lack direct functional association with phenotypic traits [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In contrast, functional markers like the Start Codon Targeted Polymorphism (SCoT) target gene-rich regions near start codons, offering higher reproducibility and closer linkage to adaptive traits[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. SCoT markers have been applied to genotype discrimination and screening for stress tolerance in a wide range of crops such as tomato and citrus[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e];[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite the availability of multiple citrus rootstocks, there are limited comparative studies integrating morphological, physiological, biochemical, and molecular analyses under PEG-simulated drought stress. Investigations on the correlations between drought tolerance, proline-related gene expression, antioxidant enzyme profiles, and SCoT-based genetic diversity in citrus rootstocks remain scarce. Therefore, the objective of this work was to: Study the drought tolerance of the four citrus rootstocks Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange under in vitro PEG-induced osmotic stress. Investigate morphological, photosynthetic, and physiological responses including proline accumulation and relative water content. Study the antioxidant enzyme activity such as POD and SOD and protein profiles under stress conditions. Genetic diversity and stress-associated molecular patterns would be investigated using SCoT markers and detection of some proline-related genes. We hypothesized those superior rootstocks for drought tolerance would show better maintenance of growth and higher photosynthetic pigment stability, enhanced proline accumulation, and different molecular and biochemical marker profiles. These results are expected to contribute further to the selection and breeding of the most appropriate drought-tolerant citrus rootstock for sustainable production under conditions of limited water supply.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Plant material\u003c/h2\u003e \u003cp\u003eIn the years 2023 and 2024, the tests were conducted in the tissue culture lab of the Horticulture Department, Faculty of Agriculture, Al-Azhar University, Nasr City, Cairo, Egypt.\u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003e2.1.2. Disinfection of explant\u003c/h2\u003e \u003cp\u003eFruits were collected from twelve-year-old trees of four citrus rootstocks: Cleopatra mandarin (\u003cem\u003eCitrus reshni\u003c/em\u003e Hort. ex Tanaka), trifoliate orange (\u003cem\u003ePoncirus trifoliata\u003c/em\u003e L. Raf.), Volkameriana lemon (\u003cem\u003eCitrus volkameriana\u003c/em\u003e Tan.), and macrophylla (\u003cem\u003eCitrus macrophylla\u003c/em\u003e Wester). Seeds of all rootstocks were harvested from mother trees maintained in the germplasm collection of the Agricultural Research Center (ARC), Giza, Egypt (30\u0026deg;30\u0026prime;1.4\u0026Prime; N, 30\u0026deg;19\u0026prime;10.9\u0026Prime; E). The fruits were submerged in 99.6% ethanol for 15 minutes after being carefully cleaned under running water for 30 minutes to get rid of any surface debris. Following this, the fruits were briefly flame-sterilized for 5 seconds under laminar airflow conditions. Seeds were carefully extracted from the fruits on sterilized paper within the laminar flow hood. After that, the seeds were ready for in vitro cultivation in Murashige and Skoog (MS) medium devoid of plant growth regulators. Drops of 0.1 N potassium hydroxide (KOH) or hydrochloric acid (HCl) were added as needed to bring the medium's pH down to 5.7. Transparent polypropylene lids were placed over sterile 100-mL glass jars that held 25 mL of medium apiece[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The media-filled jars were autoclaved under 1.5 kg/cm\u0026sup2; pressure for 20 minutes at 121\u0026deg;C. Prior to seed inoculation, the jars were allowed to cool to room temperature and kept tilted in the culture cabinet until needed. Cool white, fluorescent lamps with an intensity of 3000 lux were used to give 16-hour photoperiods while the cultures were cultured at 27\u0026deg;C for four weeks. To guarantee uniformity, each treatment was repeated three times.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e2.1.2. Cultivation and Shoot Proliferation of Citrus Rootstocks:\u003c/h2\u003e \u003cp\u003eExplants were cultivated on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L BA and 0.01 mg/L NAA using shoot tips or micro-cuttings from all evaluated citrus rootstocks [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The seeds that germinated as previously mentioned produced these explants. Cool white, fluorescent lights with an intensity of 3000 lux were used to give a 16-hour photoperiod while the cultures were kept at 27\u0026deg;C for four weeks. To guarantee the trustworthiness of the experiment, each treatment was repeated three times.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.1.3. In Vitro Mass Multiplication of Citrus Rootstocks\u003c/h2\u003e \u003cp\u003eMurashige and Skoog (MS) basal medium (1962) supplemented with 30 g/L sucrose, 1.0 mg/L BA (6-Benzylaminopurine), and 1.0 mg/L KIN (kinetin) were used to transfer axillary shoots from the various citrus rootstocks[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. For four weeks, cultures were kept in a growth chamber at 27\u0026deg;C with a 16-hour photoperiod supplied by cool white, fluorescent lights with an intensity of 3000 lux. To guarantee effective mass propagation of all evaluated rootstocks, each treatment was repeated three times.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.1.4. Induction of Abiotic Stress\u003c/h2\u003e \u003cp\u003eThe purpose of this study was to evaluate how citrus rootstocks Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and macrophylla responded to increasing drought stress in vitro. After being moved from the multiplication medium to MS media with 30 g/L sucrose, 1.0 mg/L BA, and 0.01 mg/L NAA, uniform explants were subjected to 0.0%, 4%, and 8% polyethylene glycol (PEG). Three plantlets were used in each of the three replicates of each treatment.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Data Collection: Morphological and Biochemical Traits\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.2.1. Assessment of Morphological Characteristics\u003c/h2\u003e \u003cp\u003eThe number of freshly formed shoots, shoot length (cm), and total number of leaves per shoot were measured to assess axillary shoot growth under drought stress after 30 days of culture. The vegetative response of each citrus rootstock to increasing PEG-induced drought stress was summarized by these metrics.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e2.2.2. Photosynthetic Pigment Determination\u003c/h2\u003e \u003cp\u003eFollowing the Lichtenthaler and Buschmann [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] approach, the amounts of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the leaves were measured at the conclusion of the experiment (after 30 days). After being pulverized in a mortar with 15 mL of 80% acetone, around 0.2 g of fresh leaf tissue was filtered. The absorbance of the extract was determined using a UV-Vis spectrophotometer (Jenway, Model 715) at wavelengths of 470, 663, and 646 nm. 80% acetone was used as a blank for instrument calibration. The following formulas were used to determine pigment concentrations:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:Chloroplly\\:a=12.25\\:\\times\\:A663.2-2.79\\times\\:A646.8\\:$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:Chloroplly\\:b=21.21\\:\\times\\:A646.8-5.1\\times\\:A666.2$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e\n$$\\:Carotenoids=1981000\\:\\times\\:A470-1.8\\times\\:Chl\\:a-85.02\\times\\:Chl\\:b$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eChl b, where Chl a, Chl b, total chlorophyll, and Car represent the concentrations of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids, respectively. All pigment contents were expressed on a fresh weight basis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e2.2.3. Proline Content Analysis\u003c/h2\u003e \u003cp\u003eProline levels were determined using the colorimetric method of Bates et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. After homogenizing fresh leaf tissue in 3% aqueous sulfosalicylic acid, it was filtered. After reacting to two milliliters of the filtrate with two milliliters of acid-ninhydrin and two milliliters of glacial acetic acid at 100\u0026deg;C for an hour, the mixture was chilled in an ice bath. Four milliliters of toluene were used to extract the reaction product, and toluene was used as a blank to measure absorbance at 520 nm. A standard curve was used to determine the proline concentration based on fresh weight. [(,ag proline/ml \u0026times; ml toluene) / 115.5 ixg/lzmole]/[(g sample)/5] -= ~moles proline/g of material with fresh weight.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003e2.2.4. Leaf Relative Water Content (RWC)\u003c/h2\u003e \u003cp\u003eIn accordance with (Garcı́a-Mata and Lamattina [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], the effect of PEG on leaf RWC in four citrus rootstocks was evaluated. In each replication, two leaves were chosen at random from the central section of each plant. After measuring the fresh weight (FW), the leaves were submerged in distilled water at 22\u0026deg;C for a full day to estimate the turgid weight (TW). To determine dry weight (DW), leaves were oven-dried for 48 hours at 80\u0026deg;C.\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e\n$$\\:Relative\\:water\\:content\\:\\left(\\%\\right)=\\frac{Fresh\\:weight-dry\\:weight}{turgid\\:weight-dry\\:weight}\\times\\:100$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e2.2.5. Genetic Analysis\u003c/h2\u003e \u003cp\u003eSCoT-PCR Analysis\u003c/p\u003e \u003cp\u003eSCoT-PCR amplification was carried out using the(Collard and Mackill 2009) methodology. The four citrus samples were characterized using five SCoT primers: SCoT-1 (CAACAATGGCTACCACCA), SCoT-3 (CAACAATGGCTACCACCG), SCoT-4 (CAACAATGGCTACCACCT), SCoT-10 (CAACAATGGCTACCAGCC), and SCoT-13 (ACGACATGGCGACCATCG). 10 \u0026micro;L sterile water, 10 \u0026micro;L master mix, 2.5 \u0026micro;L primer, and 2.5 \u0026micro;L genomic DNA made up the PCR reaction mixture (25 \u0026micro;L total volume).An initial denaturation at 94\u0026deg;C for three minutes, 35 cycles of 94\u0026deg;C for one minute, 50\u0026deg;C for one minute, and 72\u0026deg;C for ninety seconds, and a final extension at 72\u0026deg;C for seven minutes comprised the thermal cycling conditions. A Gel Documentation System was used to visualize the separated PCR results on 1.5% agarose gels.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e2.2.6. Detection of Proline-Related Genes\u003c/h2\u003e \u003cp\u003eDNA Extraction and PCR Amplification\u003c/p\u003e \u003cp\u003eFollowing the manufacturer's recommendations, fresh young leaf tissues from the four citrus rootstocks (M, V, C, and P) were used to extract genomic DNA using the QIAGEN BioSprint Plant DNA Kit. Before being used again, extracted DNA was kept at -20\u0026deg;C.The SbP5CS1 gene's promoter region was amplified using primers P1-F (5\u0026prime;-TTGCTGATCCCTTGCTGC-3\u0026prime;) and P1-R (5\u0026prime;-ATCCCTCCTCTCCCCATT-3\u0026prime;). A total of 25 \u0026micro;L was used for PCR reactions, which included 10 \u0026micro;L of sterile water, 10 \u0026micro;L of master mix, 2.5 \u0026micro;L of primer, and 2.5 \u0026micro;L of genomic DNA. The thermal cycling schedule included a 5-minute initial denaturation at 94\u0026deg;C, 35 cycles of 94\u0026deg;C for 30 seconds, 55\u0026deg;C for 30 seconds, and 72\u0026deg;C for 2.5 minutes, and a final 10-minute extension at 72\u0026deg;C.\u003c/p\u003e \u003cp\u003eStatistical and Molecular Data Analysis\u003c/p\u003e \u003cp\u003eA fully randomized block design was used to set up the experiment. Two-way ANOVA in Co-Stat software (Stern, 1991) was used for analysis of variance (ANOVA), and Duncan's multiple range test was used to compare means at a significance level of \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05. To reduce errors, distinct and well-resolved bands were visually assessed for molecular data. Bands were scored as present (1) or absent (0) to create a binary data matrix. The number of polymorphic bands divided by the total number of bands for each primer yielded the percentage of polymorphism. Jaccard's coefficient was used to determine the genetic similarity of the samples[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. To assess the general genetic linkages, principal component analysis (PCA) was then carried out using the D-Center module Abouseadaa et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Evaluation of Growth characteristics\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the effects of PEG treatments on the morphological characteristics of the four evaluated citrus rootstocks. In comparison to the control, the results indisputably revealed that when the PEG concentration climbed from 4% to 8% under direct (shock) treatment, the number of shoots, shoot length (cm), and leaf number reduced. However, when exposed to higher levels of water deficiency stress caused by increasing PEG concentrations from 4% to 8%, all investigated rootstocks experienced a drop in growth rate. When compared to the other rootstocks, trifoliate orange rootstocks exhibited the highest values for these morphological characteristics, suggesting a significant variation in the rootstocks' reactions to PEG treatments at both concentrations. Raising the polyethylene glycol (PEG) concentration from 4% to 8% resulted in a significant decrease in shoot number, shoot length, and leaf number across all evaluated citrus rootstocks subjected to direct (shock) treatment, along with an increase in mortality rates, according to the results shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eShows how certain citrus rootstocks cultivated in vitro were affected morphologically by drought stress using PEG\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRootstocks\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConcentration (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShoot number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eShoot length (CM)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLeaves number\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.33ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.00a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.33a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.33cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.20cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.33bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.00cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.20f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.67bcd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.67a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.50ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.67a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.33bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.80bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.67bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.33cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.90ef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.33bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.33bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.53bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.33ab\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.67de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.83cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.67bcd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.67de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.07f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.67de\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.00cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.33de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.67bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.33cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.33f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.00cde\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.00e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.10g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.00e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Treatments(T) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Rootstock(R)=\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: (Treatments x Rootstocks) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"6\" nameend=\"c3\" namest=\"c2\" rowspan=\"7\"\u003e \u003cp\u003eDuncan\u0026rsquo;s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Photosynthesis pigment evaluation\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e summarizes the effects of PEG-induced drought stress (direct shock treatment) on photosynthetic pigments, including total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids. All citrus rootstocks subjected to 4% and 8% PEG showed a marked decrease in pigment content when compared to the control. The magnitude of reduction was concentration-dependent, with 8% PEG causing the greatest decline. Among the rootstocks, trifoliate orange maintained the highest pigment levels, followed by Cleopatra mandarin, Volkameriana lemon, and Citrus macrophylla, highlighting genotype-specific tolerance to osmotic stress.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of drought stress using PEG on photosynthesis pigments of some citrus rootstocks grown in vitro.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRootstocks\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConcentration (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChlorophyll a /100g.F. W\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eChlorophyll b /100g.F. W\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eChlorophyll total/100g.F. W\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eCarotenoids/100g.F. W\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.19a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18.07ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e18.69ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.50b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.52bcd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14.32c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.71de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.07c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.26ef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.67de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.58gh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.03e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.18a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19.10a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e19.65a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.53a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.82b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15.05c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16.88cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.80b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.38e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.73d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.08fg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.86cd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16.85a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.40b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.89bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.80cd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.31cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13.66c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.21e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.60d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.00ef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.25e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.10gh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.77e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.18bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14.62c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.10cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.80e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.31d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13.85c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14.42ef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.68e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.33f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.81e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.31h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.21f\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Treatments(T) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Rootstock(R)=\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: (Treatments x Rootstocks) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"6\" nameend=\"c3\" namest=\"c2\" rowspan=\"7\"\u003e \u003cp\u003eDuncan\u0026rsquo;s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Evaluation of Biochemical and Physiological Characteristics\u003c/h2\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e3.3.1. Proline Content\u003c/h2\u003e \u003cp\u003eThe effect of PEG-induced drought stress (4% and 8%) on leaf proline content in four citrus rootstocks is presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. Increasing PEG concentrations led to a marked accumulation of proline in all rootstocks compared to the control. The highest proline levels were observed under 8% PEG, followed by 4% PEG, while the lowest values were recorded in the non-stressed control. Significant differences were found between the rootstocks, with Cleopatra mandarin having the highest proline accumulation, followed by Volkameriana lemon, Citrus macrophylla, and trifoliate orange, demonstrating genotype-specific osmotic stress responses. These results demonstrate how different the citrus rootstocks' reactions to drought stress are, with Cleopatra demonstrating the highest capacity to collect proline in stressful situations. According to the findings, there were notable genotypic differences between the rootstocks (Cleopatra\u0026thinsp;\u0026gt;\u0026thinsp;Trifoliate\u0026thinsp;\u0026gt;\u0026thinsp;Citrus macrophylla\u0026thinsp;\u0026gt;\u0026thinsp;Volkameriana lemon) and a notable increase in leaf proline content across all assessed citrus rootstocks when the concentration of polyethylene glycol (PEG) was raised from 4% to 8%. The highest accumulation was observed under 8% PEG. Plants have a well-established adaptive response to water scarcity or osmotic stress: proline buildup. It serves as a suitable osmolyte, stabilizes proteins and membranes, and scavenges reactive oxygen species (ROS).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section3\"\u003e \u003ch2\u003e3.3.2. Leaf relative water content (LRWC)\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the effects of PEG-induced drought stress (direct shock treatment) on leaf relative water content (LRWC) in the citrus rootstocks tested. All rootstocks grown on MS medium supplemented with 4% or 8% PEG had lower LRWC than the control. Among the rootstocks, Volkameriana lemon had the greatest decrease in LRWC under 8% PEG, while Cleopatra mandarin had the highest, followed by trifoliate orange. These findings show significant genotype-dependent variation, with LRWC decreasing steadily as PEG concentration climbed from 4% to 8%. This suggests that PEG-induced osmotic stress successfully decreased the amount of water present in plant tissues, resulting in dryness of the cells. A concentration-dependent link between the level of water stress and leaf water status was demonstrated by the more noticeable decrease in RWC at 8% PEG.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of drought stress using PEG on biochemical and physiological characteristics of some citrus rootstocks grown in vitro\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRootstocks\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConcentration (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eProline π/g F. W\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRWC %\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.17f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e96.36a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.60de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e81.45bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.96b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e64.08d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.40e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e97.47a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.80bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85.83b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.40a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e68.69d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.03f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95.10a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.40e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e78.51c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.70cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e54.91e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.84g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e93.17a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.20f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e68.51d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePEG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.50e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48.24f\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Treatments(T) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: Rootstock(R)=\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eLSD at 5%: (Treatments x Rootstocks) =\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"6\" nameend=\"c3\" namest=\"c2\" rowspan=\"7\"\u003e \u003cp\u003eDuncan\u0026rsquo;s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEG (8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e3.3.Genetic description\u003c/h2\u003e \u003cdiv id=\"Sec22\" class=\"Section3\"\u003e \u003ch2\u003e3.3.1. SCoT-PCR Analysis\u003c/h2\u003e \u003cp\u003eFive Start Codon-Targeted (SCoT) primers were used to evaluate the genetic similarity and polymorphism of the four citrus rootstocks\u0026mdash;Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and Citrus macrophylla (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Each primer produced five to eleven amplified fragments; SCOT-4 produced the most bands, while SCOT-10 and SCOT-13 produced the fewest. The degree of intra-genotypic variation within each rootstock was significantly lower than the inter-genotypic variance among the cultivars evaluated, despite the presence of polymorphic bands. Five Start Codon Targeted (SCoT) primers were used to assess the genetic similarity and polymorphism of the four citrus rootstocks: Cleopatra mandarin, Trifoliate orange, Volkameriana lemon, and Citrus macrophylla (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Five to eleven fragments were amplified by each primer; SCot-4 produced the most bands, while SCot-10 and SCot-13 produced the fewest.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe amplification products were between 111.9 and 1840.1 bps in size of the 37 scoreable fragments, 28 were polymorphic among the accessions, and 9 were monomorphic, according to Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, which shows that all the tested primers produced polymorphic bands. The number of polymorphic bands ranged from three to ten, and the average polymorphism/primer was 5.6. The percentage of polymorphism revealed by the different primers ranged from 50.0 to 90.9%, with an average of 72.18 percent. Amplification results from the SCoT-PCR analysis of the four citrus rootstocks ranged from 111.9 to 1840.1 bp, suggesting that the primers chosen to target a wide range of genomic regions, from tiny to sizable fragments.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eUsing five primers, SCoT markers identified genetic variation in four citrus rootstocks\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSize of fragments (bP)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal number of bands\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMonomorphic bands\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePolymorphic bands\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePolymorphism %\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSCoT 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e209.6\u0026ndash;1584.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e80.0%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSCoT 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e111.9\u0026ndash;569.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50.0%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSCoT 4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e294.4\u0026ndash;1772.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e90.9%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSCoT 10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e389.8\u0026ndash;1840.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e60.0%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSCoT 13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e762.3\u0026ndash;1637.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e80.0%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e----\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-----\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e----\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e72.18%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe genetic similarity of the four citrus rootstock genotypes in the dendrogram ranged from 0.128 to 0.961 (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Citrus macrophylla and trifoliate orange rootstocks had the highest genetic similarity (0.961) according to the biochemical and molecular genetics investigation, whereas citrus macrophylla and Cleopatra mandarin had the lowest similarity index (0.128). The significant degree of polymorphism detected by SCoT primers reflects the unique genetic organization of Cleopatra mandarin, Trifoliate orange, Volkameriana lemon, and Citrus macrophylla.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGenetic similarity relationships among four citrus rootstocks used for cluster analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCultivars\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrus macrophylla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.182\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolkameriana lemon\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.530\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.420\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrifoliate orange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.892\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.961\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.703\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e \u003ch2\u003e3.3.2. Determined of Presence proline-related genes\u003c/h2\u003e \u003cp\u003eProline-related genes were used to determine the genetic relationships between the four citrus rootstocks under investigation to assess their drought responsiveness. The findings showed that the primer (SbP5CS1) was associated with proline-related genes having a molecular weight of 485.19 kb in Table\u0026nbsp;6 and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. This suggests that while the Citrus macrophylla rootstock lacks antioxidant genes, the cultivars (Cleopatra mandarin, trifoliate orange, and Volkameriana lemon) do. The primer SbP5CS1, which amplified a 485.19 bp fragment, was used to assess the presence of genes linked to proline. The findings show that the rootstocks of Cleopatra mandarin, trifoliate orange, and Volkameriana lemon contain the proline biosynthesis gene associated with SbP5CS1. In contrast, Citrus macrophylla did not show amplification, indicating that this gene is either absent or expressed at a very low level under the conditions tested. The findings show that the rootstocks of Cleopatra mandarin, trifoliate orange, and Volkameriana lemon contain the proline biosynthesis gene associated with SbP5CS1. In contrast, Citrus macrophylla did not show amplification, indicating that this gene is either absent or expressed at a very low level under the conditions tested.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Biochemical genetic identification of Citrus rootstocks\u003c/h2\u003e \u003cdiv id=\"Sec25\" class=\"Section3\"\u003e \u003ch2\u003e3.4.1. Antioxidant enzyme activities\u003c/h2\u003e \u003cdiv id=\"Sec26\" class=\"Section4\"\u003e \u003ch2\u003e3.4.1.1. Peroxidase (POD)\u003c/h2\u003e \u003cp\u003eThe results of the electrophoresis of peroxidase in (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e7\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) showed that it can be relied upon to identify between the rootstocks and the treatments within a given item. Where it was clear, there were 2 bands with monomorphic at Rf 0.182, and 0.688. While there were 3 unique bands as Rf 0.614 characterized Citrus macrophylla, Rf 0.760 marked Volkameriana lemon, while the third at Rf 0.775 identified Cleopatra mandarin. Without the rest of the rootstock and the treatments inside. When we look at the results of the electrophoresis between the rootstocks and the treatments within the item, we find characteristic bands, identify Citrus macrophylla and treatments for the same item, we find 2 bands at Rf 0.591 and 0.729, which are found in treatments and aren\u0026rsquo;t found in the rootstock. These areas are thought to be distinctive bands of treatments and could be caused by the expression of drought-resistant genes in the rootstocks or by the action of oxidation enzymes within the cells. In the high content drought treatment, rootstock Cleopatra mandarin displayed a band at Rf 0.731; it was absent in the rootstock and other treatments. Finally, rootstock trifoliate orange that was different from the three rootstocks. The results showed that there were unique bands at Rf 0.731 in the rootstock trifoliate orange. While the results showed that 2 bands appeared in drought coefficients without origin at Rf 0.729, 0.774 and that these locations may be due to the activation of drought genes within cells. Peroxidase (POD) enzyme electrophoresis revealed distinct banding patterns among the four citrus rootstocks and across drought treatments, indicating that POD activity can serve as a biochemical marker for genotype differentiation and stress response. Two monomorphic bands at Rf 0.182 and 0.688 were observed across all cultivars, suggesting conserved POD isoforms that are constitutively expressed irrespective of genotype or stress conditions. Distinct polymorphic bands were detected among the rootstocks, with unique bands at Rf 0.614, 0.760, and 0.775 corresponding to Volkameriana lemon, Trifoliate orange, and Cleopatra mandarin, respectively.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eIsomers of Peroxidase (+/-) and their Rf value\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"16\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c16\" colnum=\"16\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBand No.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eM5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eV1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eV3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eV5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eC3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eP1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eP3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003eP5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c15\"\u003e \u003cp\u003eFrequency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphism\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"16\" nameend=\"c16\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePlus/Minus data for (Peroxidase) gel image\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.182\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.591\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.614\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.083\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eUnique\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.648\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.917\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.688\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.729\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e7\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.731\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.167\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e8\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.760\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.083\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eUnique\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e9\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.774\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.167\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e10\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.776\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.083\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eUnique\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal bands\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e\u003cb\u003e6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e\u003cb\u003e6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c16\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePolymorphis%\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"14\" nameend=\"c16\" namest=\"c3\"\u003e \u003cp\u003e\u003cb\u003e80%\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"16\"\u003e(Rf) = Relative mobility, (+) = Present, (-) = absent, (1) = control, (3, 5) = treatments\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec27\" class=\"Section4\"\u003e \u003ch2\u003e3.4.1.2. Superoxide dismutase (SOD)\u003c/h2\u003e \u003cp\u003eA polymorphism percentage of 50% is obtained from the results shown in (Table\u0026nbsp;8) which show the presence of two bands overall: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632. Overall, no distinct bands or significant variations between the cultivars and treatments were found by electrophoretic analysis of SOD. A polymorphism percentage of 50% is obtained from the results shown in Table\u0026nbsp;8 and Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, which show the presence of two bands overall: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632. Overall, electrophoretic analysis of SOD across the cultivars and treatments revealed no unique bands or notable differences among them. The four citrus rootstocks showed two bands on superoxide dismutase (SOD) electrophoresis: one polymorphic band at Rf 0.804 and one monomorphic band at Rf 0.632, resulting in a 50% overall polymorphism. Unlike peroxidase (POD), the SOD banding pattern showed limited differentiation among cultivars and treatments, with no unique bands attributable to either genotype or stress condition. The predominance of a monomorphic band suggests that a constitutive SOD isoform is conserved across all citrus rootstocks, providing a basal level of ROS scavenging to mitigate oxidative stress.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"18\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c16\" colnum=\"16\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c17\" colnum=\"17\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c18\" colnum=\"18\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"18\" nameend=\"c18\" namest=\"c1\"\u003e \u003cp\u003eTable\u0026nbsp;8. Isomers of Superoxide dismutase (+/-) and their Rf value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBand No.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eM5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eV1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eV3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eV5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eC3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eP1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eP3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003eP5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003eFrequency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphism\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c18\" namest=\"c17\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"17\" nameend=\"c17\" namest=\"c1\"\u003e \u003cp\u003ePlus/Minus data for (SOD) gel image.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c18\" namest=\"c18\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.632\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c18\" namest=\"c17\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.804\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.833\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c18\" namest=\"c17\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eTotal bands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c16\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c18\" namest=\"c17\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePolymorphism %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"15\" nameend=\"c17\" namest=\"c3\"\u003e \u003cp\u003e50%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c18\" namest=\"c18\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"18\"\u003e(Rf) = Relative mobility, (+) = Present, (-) = absent, (1) = control, (3, 5) = treatments\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec28\" class=\"Section2\"\u003e \u003ch2\u003e3.5. Protein electrophoresis\u003c/h2\u003e \u003cdiv id=\"Sec29\" class=\"Section3\"\u003e \u003ch2\u003e3.5.1. SDS-PAGE protein banding patterns of citrus leaves\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e displays the SDS-PAGE analysis of the four citrus rootstocks. The molecular weights of the 17 protein bands that were found ranged from 11.838 kDa to 83.745 kDa. Cleopatra mandarin has the fewest bands (8), while Volkameriana lemon had the most (15). Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e9\u003c/span\u003e summarizes the bands' existence and absence, which were noted as (+) and (\u0026minus;), respectively. Eleven of the bands were polymorphic and six were monomorphic, making up a polymorphism percentage of 64.7%. Except for one band found only in trifoliate orange under the testing conditions, no distinct bands were seen in any of the rootstocks. No unique bands were observed across the rootstocks, except for a single band detected exclusively in trifoliate orange under the tested conditions. Analysis of band presence and absence indicated that six bands were monomorphic, present in all rootstocks, reflecting conserved proteins likely involved in basic cellular functions. In contrast, eleven bands were polymorphic, resulting in an overall polymorphism of 64.7%, which demonstrates substantial protein-level variability among the genotypes. No unique bands were observed among the examined rootstocks, except for one unique band detected in trifoliate orange rootstock under specific treatments, suggesting that most protein differences are quantitative or shared among genotypes rather than strictly qualitative.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 9\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eData matrix indicating the presence or lack of bands in leaf protein electrophoretic banding patterns for the four citrus rootstocks\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"16\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c16\" colnum=\"16\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBand No.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMW\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eM5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eV1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eV3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eV5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eC3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eP1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eP3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003eP5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c15\"\u003e \u003cp\u003eFrequency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphism\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"16\" nameend=\"c16\" namest=\"c1\"\u003e \u003cp\u003ePlus/Minus data for (SDS-PAGE) protein gel image\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e83.745\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.167\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80.554\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65.964\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60.863\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56.313\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49.840\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.583\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e7\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47.412\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e8\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45.102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.333\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e9\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e10\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40.140\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e11\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.122\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.053\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.417\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e13\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.346\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.667\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e14\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.314\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e15\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.747\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e16\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.668\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e0.500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003ePolymorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e17\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.838\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003eMonomorphic\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal bands\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c16\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePolymorphism (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"14\" nameend=\"c16\" namest=\"c3\"\u003e \u003cp\u003e64.706%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab8\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 10\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCorrelation matrix showing the extent of Morphological, photosynthetic pigment, biochemical, and physiological characteristics in citrus rootstocks growing in vitro conditions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eShoot number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eShoot length c/cm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLeaves number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRWC %\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eChlorophyell a\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eChlorophyell B\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTotal Chlorophyell\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eCarotenoides\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eProline\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShoot number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShoot length c/cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.879**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeaves number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.951**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.922**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRWC %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.874**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.910**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.915**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChlorophyell a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.8764**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.922**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.871**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.957**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChlorophyell B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.873**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.903**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.855**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.940**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.996**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal Chlorophyell\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.917**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.927**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.913**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.975**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.989**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.980**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarotenoides\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.770**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.873**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.814**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.686**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.723**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.705**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.731**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProline\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.330*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.287*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-0.249*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.503**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.567**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.585**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.545**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.118*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"10\" nameend=\"c10\" namest=\"c1\"\u003e \u003cp\u003eCorrelation is significant at the 5% level**; Correlation is significant at the 1% level *\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe parameters in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e showed that shoot number, shoot length (cm), leaf number, RWC%, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and proline were biplotted to the different levels of drought stress caused by the PEG treatments (control, 4% PEG, and 8% PEG) using Principal Component Analysis (PCA). Approximately 93.8%, 91.5%, 96.6%, and 97.1% of the total variance was explained by the first principal component (PC1), whereas approximately 6.2%, 8.5%, 3.4%, and 2.9% were explained by the second principal component (PC2).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab9\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 11\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePrincipal component analysis contribution to eigenvalue, variance, and cumulative variance\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMacrophylla\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eCleopatra mandarin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003ePoncirus trifoliata\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eVolkamriana limon\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrincipal component\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ePC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ePC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ePC2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEigenvalue\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5. 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7. 6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3. 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2. 6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93. 8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e91.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8. 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e96.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e97. 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCumulative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93. 8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e91. 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e96.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e97. 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabc\" border=\"1\"\u003e \u003ccolgroup cols=\"1\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec30\" class=\"Section2\"\u003e \u003ch2\u003e4.6. Correlation matrix and PCA\u003c/h2\u003e \u003cp\u003eThe correlation study's findings demonstrated a robust paired relationship between the morphological, physiological, biochemical, and photosynthetic pigment characteristics of citrus rootstocks grown in vitro. The strength and direction of these relationships varied among the PEG-induced water stress treatments (0.0%, 4%, and 8%), which were associated with progressively increasing levels of drought stress. The physiological characteristics of chlorophyll concentration showed a highly significant and positive correlation with shoot number, shoot length (cm), leaf number, relative water content (RWC%), chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids across all PEG-induced water stress levels. On Proline, on the other hand, significantly altered the relationships between the morphological, physiological, and biochemical traits of citrus rootstocks by exhibiting a strong negative connection with most morphological and pigment-related indicators. PCA highlighted the first two components of 9 variables, where the first and second components were 93.8%, 91.5%, 96.6%, and 97.1% of the total variance, while the second principal component (PC2) explained around 6.2%, 8.5%, 3.4%, and 2.9%, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e and Table \u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e10\u003c/span\u003e. Explants of drought stress brought on by the PEG treatments (control, 4% PEG, and 8% PEG) are mostly located at the upper right side of the plot and have a strong positive correlation with the first component: Shoot number, shoot length (cm), leaf number, RWC (%), chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids at the level of 4% PEG at the center of the plot, However, the explants that received 8% PEG treatment were primarily seen on the left side of the plot, indicating a significant rise in proline accumulation. These results indicate that 4% PEG-induced drought stress caused significant variation among the citrus rootstocks studied in their morphological, biochemical, and physiological characteristics.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThese findings clearly indicate that PEG-induced osmotic stress has a detrimental effect on vegetative growth and highlights the susceptibility of citrus genotypes to water-deficit conditions. The observed reduction in morphological features is consistent with previous studies that found higher PEG concentrations reduce shoot elongation, leaf expansion, and total biomass accumulation due to decreased cell turgor and water uptake[15];[16]. The growth medium's osmotic potential, which PEG produces, limits the amount of water available and causes cellular dehydration, which prevents cell division and growth[17];[18]. According to the current study, this causes plants to have smaller leaves, shorter shoots, and less branching. According to (Ghosh et al.,\u0026nbsp;[19]; Memon et al.,\u0026nbsp;[20], the higher mortality rate at 8% PEG indicates that the applied osmotic stress surpassed the tolerance threshold of most tested rootstocks, resulting in irreversible cellular damage and loss of viability. The substantial variation in how different rootstocks react to PEG treatments emphasizes how crucial genetic background is in determining drought tolerance. Trifoliate orange showed the highest values for shoot number, shoot length, and leaf number under both stress levels in the current study, indicating a higher ability to respond to osmotic pressure and better growth maintenance in water-limited environments. Tolerant rootstocks exposed to PEG-induced stress maintained higher relative water content (RWC), membrane stability index (MSI), and chlorophyll fluorescence parameters, according to recent studies that reported similar genotype-dependent responses[21];[1]. These characteristics are frequently linked to effective osmotic adjustment mechanisms, such as increased root hydraulic conductance, improved antioxidant defense, and osmolyte accumulation (proline, soluble sugars)[22]. Furthermore, a highly developed and branching root system that promotes better water absorption and preserves cell turgidity even in the face of osmotic stress may be the cause of trifoliate orange's morphological robustness. In contrast to sensitive genotypes, tolerant rootstocks maintained more root tips, more root surface area, and longer total root length, according to high-throughput phenotyping of citrus genotypes under controlled drought circumstances[23]. Rather than promoting actual physiological tolerance, these traits help people escape drought better. Therefore, rather than using metabolic tolerance mechanisms, trifoliate oranges may predominantly use drought avoidance tactics through efficient water uptake and cautious water use. All things considered, the present findings are in line with earlier research that emphasizes the effectiveness of PEG treatments as a controlled and repeatable paradigm for determining the drought resilience of citrus genotypes[24];[25]. Field drought conditions cannot be accurately replicated by PEG-induced osmotic stress due to the lack of additional environmental factors like temperature fluctuations, soil texture, and microbial interactions[26]. Therefore, a more thorough evaluation of rootstock performance and durability will be possible by combining PEG-based laboratory screening with field assessments conducted under natural drought.\u003c/p\u003e\n\u003cp\u003eThe reduction in chlorophyll content under drought stress is typically caused by a variety of physiological and biochemical factors, including decreased chlorophyll biosynthesis, increased activity of enzymes that break down chlorophyll, such as chlorophyllase, and oxidative damage to chloroplast membranes caused by the accumulation of reactive oxygen species (ROS)\u0026nbsp;[27];[28]. Limited water availability under PEG-induced water deficit decreases gas exchange and leaf turgor, which causes stomatal closure and a reduction in carbon fixation. This, in turn, slows down the generation of chlorophyll and speeds up the deterioration of pigments\u0026nbsp;[29]. Comparably, under PEG stress, carotenoid content also dropped, but less sharply than chlorophyll levels. Because they dissipate excess electricity and quench singlet oxygen, carotenoids are essential for photoprotection\u0026nbsp;[30]. The observed decline could be due to a general deterioration of the photosynthetic machinery and a decrease in antioxidant defense capabilities under severe osmotic stress. However, maintaining greater carotenoid levels is believed to be an essential adaptation strategy to reduce photooxidative damage during a water scarcity[31];[32]. Citrus rootstocks showed notable variations, suggesting genotype-dependent responses in pigment maintenance under osmotic stress. Under both PEG concentrations, trifoliate orange had the highest levels of carotenoid and chlorophyll, followed by Cleopatra mandarin, Volkameriana lemon, and Citrus macrophylla. This result suggests that Trifoliate orange has a greater capacity to preserve photosynthetic pigment integrity under drought stress. Similar genotype-specific differences have been documented, where tolerant rootstocks maintain higher pigment levels and photochemical efficiency (Fv/Fm) due to more effective antioxidant activity and osmotic adjustment[33]. Therefore, maintaining higher chlorophyll and carotenoid levels under PEG-induced drought can be considered a key indicator of drought tolerance in citrus. The ability of Trifoliate orange to retain these Thus, sustaining increased levels of carotenoid and chlorophyll under PEG-induced drought might be regarded as a crucial sign of citrus drought tolerance. Trifoliate orange's improved photosynthetic performance and growth stability under stress are probably influenced by its capacity to retain these pigments, which also supports its appropriateness as a rootstock in settings with low water.\u003c/p\u003e\n\u003cp\u003eThe highest accumulation was observed under 8% PEG. Plants have a well-established adaptive response to water scarcity or osmotic stress: proline buildup. It serves as a suitable osmolyte, stabilizes proteins and membranes, and scavenges reactive oxygen species (ROS). In citrus and other crops, studies conducted in the past ten years have confirmed that proline levels rise in response to osmotic, salt, or drought stress[34]. Differential proline buildup has been documented in citrus rootstocks. For instance, proline accumulation in leaves was utilized as a possible biochemical marker for water-stress resistance in sweet orange grafted combinations when there was a natural water scarcity in orchards[35]. Similarly, one of the biochemical responses associated with improved recovery following re-watering in a recent screening of nine citrus rootstocks under controlled drought stress was enhanced proline accumulation[36]. Our data's genotypic variance in proline accumulation points to a difference in the metabolic adaptation of rootstocks to osmotic stress. The Cleopatra rootstock's highest proline levels may suggest a robust osmotic adjustment system, which maintains cell turgor by collecting solutes to compensate for cellular water loss. On the other hand, more proline may not always indicate greater tolerance but rather a higher stress burden (more damage). In fact, according to some research, high proline can indicate the degree of stress rather than actual tolerance[37]. The dose-dependent pattern (higher PEG → higher proline) is consistent with recognized stress reactions. Higher osmotic pressure promotes the biosynthesis of proline by upregulating important enzymes like Δ¹-pyrroline-5-carboxylate synthetase (P5CS) and decreasing proline dehydrogenase (ProDH) activity. As a result, the proline findings support the hypothesis that biochemical osmotic adjustment plays an important role in citrus rootstocks' drought response to PEG-induced stress. They underline the need to use proline values as a screening parameter when evaluating rootstocks. Proline accumulation is most useful when combined with physiological (RWC, membrane stability), morphological (root/shoot properties), and pigment/photochemical data. As a result, the proline findings support the hypothesis that biochemical osmotic adjustment plays an important role in citrus rootstocks' drought response to PEG-induced stress. They underline the need to use proline values as a screening parameter when evaluating rootstocks. Proline accumulation is particularly valuable when combined with physiological (RWC, membrane stability), morphological (root/shoot properties), and pigment/photochemical data[38].\u003c/p\u003e\n\u003cp\u003eSeveral studies have reported that PEG treatments mimic water-deficit circumstances by reducing the culture medium's osmotic potential, which limits water absorption and reduces tissue hydration[21]. These outcomes are consistent with our findings. RWC is a well-known physiological indicator of plant water status because it shows the balance between water supply and transpiration losses. A decrease in RWC during PEG stress indicates reduced water intake and increased water loss due to lower root hydraulic conductivity and stomatal closure[16]. Differences in the citrus rootstocks' capacity to hold onto water under osmotic stress are highlighted by the diversity seen among them. Volkameriana lemon had the lowest RWC values, suggesting a higher vulnerability to dehydration, while Cleopatra Mandarin retained the greatest RWC values at both 4% and 8% PEG, followed by Trifoliate orange. Water retention capacity genotypic variability points to inherent physiological variations that may be associated with osmotic adjustment potential, cuticular or stomatal control, and root system design. Similar genotype-dependent alterations in RWC have been seen in citrus and related species under PEG or drought stress, with resistant rootstocks maintaining higher RWC and relative turgidity\u0026nbsp;[39];[21]. Under osmotic stress, plants typically attempt to maintain turgor pressure by accumulating compatible solutes such proline and soluble sugars; nevertheless, RWC dramatically decreases when stress exceeds the plant's capacity to react to osmotic pressure[40]. This pattern is supported by the current study's findings, which show that RWC significantly decreased across all rootstocks at greater PEG concentrations. Better drought resistance is typically linked to maintaining higher RWC under osmotic stress or drought, as this permits ongoing photosynthesis, metabolic activity, and cell growth. Stronger antioxidant systems that lessen membrane damage, improved osmotic adjustment through solute buildup, and increased root hydraulic conductivity are all common characteristics of rootstocks that can sustain higher RWC[41];[42]. According to the current study, Cleopatra mandarin and trifoliate orange exhibit superior RWC maintenance, which may be a sign of more effective water conservation techniques. This could be due to structural characteristics that reduce water loss and osmotic adjustment, which is reflected in greater proline levels. On the other hand, Volkameriana lemons' significant RWC reduction indicates a restricted ability to regulate osmotically or minimize water loss, which leads to a larger loss of turgor during PEG stress. Volkameriana lemons have also been found in earlier studies to be very drought-sensitive, showing decreased RWC and membrane integrity under comparable stressors[43]. Therefore, the current results corroborate the idea that variations in RWC between citrus rootstocks under PEG-induced stress can be used as accurate physiological indicators to differentiate between genotypes that are tolerant and those that are sensitive. All things considered, the data show that RWC is a sensitive measure of water imbalance brought on by drought in citrus rootstocks and that it can successfully supplement morphological and biochemical (such as proline build up) evaluations in determining drought resistance. The better physiological robustness of Cleopatra mandarin and trifoliate orange, as well as their potential as viable rootstocks for citrus-growing locations that are prone to drought, is demonstrated by their capacity to retain higher RWC under osmotic stress.\u003c/p\u003e\n\u003cp\u003eThe idea that SCoT markers preferentially target functional regions close to the ATG start codon, which may harbor higher sequence variability, is supported by the variation in amplification that reflects variations in primer binding sites across the genomes of the tested rootstocks[6]. According to the research, inter-genotype variance was substantially more than intra-genotype polymorphism, which was comparatively modest. According to this pattern, the four rootstocks exhibit distinct divergence from one another while remaining genetically stable within themselves. Because it suggests the possibility of combining different genetic traits across rootstocks to improve stress tolerance, growth performance, or other desired horticultural traits, such interspecific variation is beneficial for breeding programs and germplasm conservation[5]. Given the greater number of polymorphic bands seen with SCot-4, it is likely that this primer targets more changeable genomic areas, such as coding sequences that affect stress-response pathways or gene expression. The complementing aspect of numerous SCoT primers in capturing total genetic variation is highlighted by the possibility that primers with fewer bands will amplify more conserved areas. All things considered, the findings show that SCoT markers are useful for identifying genetic variations between citrus rootstocks\u0026nbsp;[6]. Their simplicity, dependability, and ability to target gene-rich regions make them a reliable approach for genotype identification, genetic diversity evaluation, and potential marker-assisted selection in citrus breeding programs[44]. Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange may all be clearly separated from one another at the molecular level, which offers important information for hybridization and rootstock selection tactics.\u003c/p\u003e\n\u003cp\u003eThis broad range of sizes is in line with earlier research that demonstrated that SCoT primers amplify areas surrounding the start codon, which can change significantly in length because of variations in coding sequences, untranslated regions, and introns[45]. The significant degree of polymorphism detected by SCoT primers reflects the unique genetic organization of Cleopatra mandarin, trifoliate orange, Volkameriana lemon, and Citrus macrophylla. This type of polymorphism is highly helpful for breeding and conservation programs because it enables genotype discrimination, the identification of genetically different accessions, and the potential selection of rootstocks with superior traits[46].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis type of polymorphism is highly helpful for breeding and conservation programs because it enables genotype discrimination, the identification of genetically different accessions, and the potential selection of rootstocks with superior traits[47]. Additionally, the dendrogram offers light on how well molecular and biochemical tests match up. Given how similar Citrus macrophylla and Trifoliate orange are, it is possible that both rootstocks share physiological characteristics like proline accumulation or drought tolerance in addition to genetic regions. Both similarities might be used to select different rootstocks. On the other hand, Cleopatra mandarin's increased RWC and proline content under PEG-induced stress may be related to its genetic divergence, suggesting that rootstocks may have different functions[40].\u003c/p\u003e\n\u003cp\u003eAs an osmoprotectant, ROS scavenger, and cellular structural stabilizer, proline accumulation is a known response to drought stress[48]. The greater proline levels seen in Cleopatra mandarin, trifoliate orange, and Volkameriana lemon under PEG-induced drought stress are consistent with the presence of proline-related genes in these cultivars. This link implies that these genotypes have an active proline biosynthesis pathway, likely mediated by Δ¹-pyrroline-5-carboxylate synthetase (P5CS), which contributes to their enhanced drought tolerance[40]. Citrus macrophylla lower proline accumulation and diminished ability to sustain cellular osmotic balance during drought stress may be attributable to the lack of SbP5CS1 amplification. Similar results have been reported for other citrus and horticulture species, where variations in drought tolerance among genotypes are correlated with the presence or expression of P5CS and other proline-related genes[27];[49]. The findings underscore the usefulness of molecular markers aimed at stress-responsive genes in assessing the genetic potential of rootstocks. Identifying functional genes associated with osmotic adjustment yields a mechanistic insight into genotype-specific drought responses and provides a molecular foundation for selecting rootstocks with enhanced stress resilience. The conclusion that Cleopatra mandarin, trifoliate orange, and Volkameriana lemon are better adapted to drought stress than Citrus macrophylla is reinforced by the combined analysis of physiological data (proline accumulation, RWC) and gene presence.\u003c/p\u003e\n\u003cp\u003eThese unique bands may reflect isoform-specific expression of POD enzymes linked to genetic variation among cultivars[50];[51]. Such cultivar-specific isoforms are useful for biochemical identification and indicate that the constitutive antioxidant capacity varies among rootstocks. When examining the impact of drought treatments, additional characteristic bands appeared that were absent from control plants. Bands at Rf 0.591 and 0.729 were detected across treatments but not in the rootstock controls, suggesting inducible POD isoforms activated under water deficit conditions. Similarly, at extreme PEG stress, cultivar-specific inducible bands were seen (Cleopatra mandarin at Rf 0.731), indicating the induction of POD isoforms in response to oxidative stress brought on by drought. These findings corroborate earlier research showing that drought stress increases the expression and activity of antioxidant enzymes, such as POD, which scavenge reactive oxygen species (ROS) and shield cellular components[52]. Interestingly, rootstock Trifoliate orange exhibited unique bands at Rf 0.731, while additional bands at Rf 0.729 and 0.774 appeared only under drought stress, suggesting both constitutive and inducible defense mechanisms. The observed physiological and biochemical reactions, such as proline buildup and maintenance of relative water content, are compatible with the activation of these isoforms, which most likely reflects the expression of drought-responsive genes encoding antioxidant enzymes. POD electrophoresis demonstrated both genotype-specific and stress-induced isoforms, highlighting the dual role of peroxidase as a molecular marker for cultivar identification and a functional marker for drought tolerance. Integrating these biochemical data with molecular markers (SCoT-PCR) and physiological traits provides a comprehensive approach for selecting citrus rootstocks with enhanced stress resilience.\u003c/p\u003e\n\u003cp\u003eThe presence of a single polymorphic band indicates minor variation among genotypes, but this variation was not sufficient to distinguish the rootstocks or drought treatments effectively. According to reports (Gill and Tuteja\u0026nbsp;[53]; Wang et al.\u0026nbsp;[42], inducible responses may be more subtle or post-translationally regulated, whereas SOD isoforms are frequently constitutively expressed in plants, acting as the first line of defense against superoxide radicals generated under stress. The absence of unique bands under drought stress implies that SOD activity in these citrus rootstocks may not vary significantly at the isoform level, and the stress response may instead be mediated by quantitative changes in enzyme activity rather than qualitative changes in isoforms. This contrasts with POD, which displayed clear cultivar-specific and stress-inducible isoforms, reflecting its more dynamic response to water deficit conditions.\u003c/p\u003e\n\u003cp\u003eThe absence of multiple unique bands indicates that drought-induced protein expression may not result in entirely novel polypeptides but rather in differential expression or accumulation of pre-existing proteins, which aligns with previous studies showing that abiotic stress often modulates protein abundance rather than creating new protein species[54]. The high polymorphism observed in the protein profiles highlights genetic and biochemical variability among citrus rootstocks, supporting their differentiation at the protein level. According to (Farooq et al. [55], proteins with molecular weights between 11 and 84 kDa may comprise antioxidant defense components, osmoprotective proteins, and stress-related enzymes that aid in drought tolerance. In line with the physiological and biochemical characteristics previously noted, such as increased RWC and antioxidant enzyme activity, the larger number of bands in Volkameriana lemon suggests a more complex protein response mechanism, possibly reflecting higher adaptive capacity under stress conditions. SDS-PAGE protein profiling complements molecular markers and physiological assays, providing an additional layer of evidence for the genetic and biochemical diversity among citrus rootstocks and their responses to drought stress. The identification of rootstocks with greater stress tolerance is further supported by the integration of these protein data with proline accumulation and antioxidant enzyme activity.\u003c/p\u003e"},{"header":"5. Conclusions","content":"\u003cp\u003eIn the current study, we have demonstrated the ability of in vitro PEG-induced osmotic stress to successfully assess drought tolerance among four citrus rootstocks: Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange. The integrated study of the morphological, physiological, biochemical, and molecular parameters expressed evident genotype-dependent responses to drought stress. PEG-induced water deficit significantly reduced the vegetative growth and photosynthetic pigment contents for all the tested rootstocks, with higher values recorded at 8% PEG. Cleopatra mandarin and trifoliate orange presented better drought tolerance through maintaining higher shoot growth, leaf number, and pigment stability than those in Volkameriana lemon and Citrus macrophylla. Physiological measurements indicated that the drought-tolerant rootstocks consistently had higher relative water content and a greater accumulation of proline under stress, demonstrating positive osmotic adjustment mechanisms.\u003c/p\u003e \u003cp\u003eMolecular studies were done using SCoT markers, which indicated high genetic diversity among rootstocks, with the percentage of polymorphism exceeding 70%. Proline-related genes, such as SbP5CS1, were detected in Cleopatra mandarin, trifoliate orange, and Volkameriana lemon but not in Citrus macrophylla, thus correlating with the differences observed in proline accumulation and drought tolerance. Biochemical profiling showed that POD isoforms acted as an effective stress-responsive marker, which exhibited constitutive as well as inducible patterns under drought stress, while SOD was more conserved among genotypes. Cleopatra mandarin was found to be the most drought-tolerant, followed by trifoliate orange, Volkameriana lemon, and Citrus macrophylla. The strong correlations between morphological traits (shoot number, length), physiological parameters (RWC, pigments), and biochemical markers (proline, antioxidant enzymes) prove that this multi-level screening approach is effective. These findings support the use of PEG-induced osmotic stress as a reliable in vitro screening protocol for the assessment of drought tolerance in citrus rootstocks. By combining SCoT markers with physiological and biochemical analyses, a sound procedure is developed for identifying the genotypes resilient against drought conditions. Thus, Cleopatra mandarin has emerged as one of the more promising rootstocks for cultivation in water-scarce regions as well as in breeding programs seeking to enhance drought tolerance in citrus.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirmed that the institutional committee and licensing committee approved the experiments, including all relevant details and that all experiments have been performed in accordance with \u0026nbsp;specified named guidelines and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe article contains no such material that may be unlawful, defamatory, or which would, if published, in any way whatsoever, violate the terms and conditions as laid down in the agreement.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial and non-financial relationships that could be construed as a potential conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe original contributions presented in the study are included in the\u003cbr\u003e\u0026nbsp;549 article; further inquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization, H.F.A. and A.E.H.; methodology, H.F.A.,A.E.H., A.N.A., I.A.E., M.E.A., A.E.A; software, A.E.H., A.A.S.; validation, A.E.H., A.N.A., and A.A.S.; formal analysis, A.E.H.,\u0026nbsp;H.F.A.,\u0026nbsp;I.A.E. and A.N.A.,; investigation,\u0026nbsp;A.E.A; resources, A.E.H.,\u0026nbsp;I.A.E., and\u0026nbsp;A.N.A.; writing\u0026mdash;original draft preparation,\u0026nbsp;H.F.A.,\u0026nbsp;A.E.H.,\u0026nbsp;I.A.E.,\u0026nbsp;A.E.A., and M.E.A. ; writing\u0026mdash;review and editing H.F.A., A.E.H., M.H.F.M.H.F. and A.M.A.; visualization, A.N.A., I.A.E. and M.E.A.; supervision, A.E.H. ; project administration, A.M.A.; funding acquisition, A.M.A.; All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was funded by Ongoing Research Funding Program (ORF-2026-334), King Saud University, Riyadh, Saudi Arabia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors extend their appreciation to Ongoing Research Funding Program (ORF-2026-334), King Saud University, Riyadh, Saudi Arabia. \u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMorade AS, Sharma RM, Dubey AK, Sathee L, Kumar S, Kadam DM, et al. 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Plant Physiol Biochem. 2019;141:353\u0026ndash;69. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.plaphy.2019.04.039\u003c/span\u003e\u003cspan address=\"10.1016/j.plaphy.2019.04.039\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-plant-biology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pbio","sideBox":"Learn more about [BMC Plant Biology](http://bmcplantbiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pbio/default.aspx","title":"BMC Plant Biology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"protein electrophoresis, photosynthetic pigments, isozyme markers, enzyme activity, scot-pcr","lastPublishedDoi":"10.21203/rs.3.rs-8428516/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8428516/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCitrus is one of the most widely planted fruit crops in the world, yet its growth and productivity are extremely susceptible to abiotic stresses, especially salinity and drought. With increasing climate change, water scarcity is becoming a major challenge, making the development of drought-tolerant rootstocks an important target in citrus biotechnology. The tolerance responses of four citrus rootstocks Citrus macrophylla, Volkameriana lemon, Cleopatra mandarin, and trifoliate orange under osmotic stress caused by polyethylene glycol (PEG) were assessed in this study. To replicate drought conditions, PEG-6000 shock treatments at doses of 0%, 4%, and 8% were applied to in vitro cells cultivated in 2024. Antioxidant enzyme activity, molecular characteristics, biochemical reactions (chlorophyll a, chlorophyll b, carotenoids, and relative water content), and morphological parameters (shoot number, shoot length, and leaf number) were all noted. PEG stress significantly reduced all growth and photosynthetic traits, while proline accumulation and antioxidant enzyme activity increased compared with the control, indicating activation of stress defense mechanisms. Genetic analysis using protein electrophoresis and peroxidase isozymes revealed banding pattern variations among rootstocks and treatments, demonstrating the usefulness of these biochemical markers in detecting genetic diversity under stress. Based on the combined results, Cleopatra mandarin showed the highest drought tolerance, followed by Citrus macrophylla, Volkameriana lemon, and Trifoliate orange. These findings suggest that the evaluated characteristics are effective for screening drought tolerance in citrus. The study highlights the potential of drought-tolerant rootstocks, particularly Cleopatra mandarin, for improving citrus adaptation and productivity under future water-limited environmental conditions.\u003c/p\u003e","manuscriptTitle":"Evaluating Citrus Rootstock Tolerance to Osmotic Stress Induced by PEG in Vitro","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-13 14:36:42","doi":"10.21203/rs.3.rs-8428516/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-13T18:24:29+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-11T11:06:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"66650969852473435916452531093161429179","date":"2026-04-03T07:50:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"237972375292009541525850750845840582128","date":"2026-04-03T07:16:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"272661070367501726131316436551084453355","date":"2026-04-02T15:26:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250743643236206048907825465777776068640","date":"2026-04-01T08:34:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-17T18:03:39+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-17T09:25:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"219129775143151577517154631678828036864","date":"2026-03-06T14:36:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"115392837170958921457384820784378483583","date":"2026-02-18T14:10:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"326646445481427717788932767117696596508","date":"2026-02-18T08:13:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"107376556059414527858419706365270122448","date":"2026-02-16T13:37:29+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-10T10:05:31+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-10T05:29:47+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-10T05:14:15+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-09T19:35:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Plant Biology","date":"2026-02-09T19:29:09+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-plant-biology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pbio","sideBox":"Learn more about [BMC Plant Biology](http://bmcplantbiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pbio/default.aspx","title":"BMC Plant Biology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c75315cd-450b-4bc2-aa44-8d8b2dd14c31","owner":[],"postedDate":"February 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-29T19:38:19+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-13 14:36:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8428516","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8428516","identity":"rs-8428516","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}