Physical basis of host plant resistance in rapeseed and mustard against mustard aphid, Lipaphis erysimi (Kaltenbach)

Physical basis of host plant resistance in rapeseed and mustard against mustard aphid, Lipaphis erysimi (Kaltenbach) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Physical basis of host plant resistance in rapeseed and mustard against mustard aphid, Lipaphis erysimi (Kaltenbach) Ajai R rangesan, Ngangom Uma Devi, Mougdha Dutta This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7303385/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Dec, 2025 Read the published version in Arthropod-Plant Interactions → Version 1 posted You are reading this latest preprint version Abstract Rapeseed-mustard ( Brassica spp.) is a vital oilseed crop in India, frequently affected by the mustard aphid, Lipaphis erysimi (Kaltenbach), a major sap-sucking pest that causes substantial yield losses. Considering the drawbacks of chemical control, host plant resistance offers a sustainable alternative. The present study was conducted under protected conditions to assess the physical basis of resistance in ten rapeseed-mustard genotypes against L. erysimi . Significant genotypic variations were observed in aphid population, percentage of infested siliques, and aphid multiplication rate across crop stages. PM 25, PM 26, and DRMR 150 − 35 consistently recorded lower aphid infestations and were categorized as resistant, whereas IC 491023 and YST 151 were highly susceptible. Among the physical traits, surface wax content showed a strong negative correlation with aphid population, suggesting its critical role in resistance. PM 25 exhibited the highest wax content (7.30%), contributing to its superior resistance. The findings indicate that physical traits like surface wax act as a first line of defense by hindering aphid colonization and feeding. This study highlights the potential of integrating such traits into breeding programs, with PM 25 emerging as a promising genotype for developing aphid-resistant varieties. Lipaphis erysimi Rapeseed-mustard genotype Surface wax Host plant resistance Figures Figure 1 Figure 2 Introduction Rapeseed-mustard ( Brassica spp.) is among the most important oilseed crops in India, contributing approximately 20–22% to the country's total oilseed production (Kumrawat & Yadav, 2018 ). However, its productivity is severely constrained by the mustard aphid, Lipaphis erysimi (Kaltenbach) (Hemiptera: Aphididae), a destructive pest that causes yield losses ranging from 9–96%, depending on the crop stage and infestation severity (Mandal et al., 2012 ). This aphid damages the crop by feeding on phloem sap, reducing seed set and oil content, and excreting honeydew that promotes sooty mould, thereby interfering with photosynthesis (Mandal et al., 2012 ). In addition, it serves as a vector of several plant viruses (Banerjee et al ., 2004). L. erysimi exhibits parthenogenetic and viviparous reproduction, completing up to 45 generations per year under favorable conditions (Basavaraju et al., 1994 ). Its rapid multiplication and mobility complicate effective chemical control. Although systemic insecticides such as imidacloprid and dimethoate are commonly used (Singh et al., 2007 ; Mishra & Singh, 2019 ), over-reliance has led to the development of resistance, pest resurgence, environmental hazards, and negative impacts on beneficial insects (Singh & Sharma, 2002 ; Sarkar & Kumar, 2022 ). Host plant resistance offers a sustainable, ecologically sound approach to pest management. Resistance mechanisms can be morphological or biochemical, including antixenosis, antibiosis, and tolerance (Painter, 1951 ; Stadler & Dixon, 2005 ). Physical traits-such as trichome density, cuticle thickness, and surface wax-act as the first line of defense, influencing aphid landing, probing, and feeding behavior (Bennett & Wallsgrove, 1994 ; Smith & Boyko, 2007 ). In particular, epicuticular waxes have been shown to interfere with aphid colonization and are negatively correlated with infestation levels (Samal et al., 2021 ). Considering these factors, the present study was undertaken to evaluate the physical traits contributing to resistance in selected rapeseed-mustard genotypes against L. erysimi under protected conditions. Materials and methods The study was conducted during the 2024–25 growing season under controlled conditions at the Polyhouse facility of the College of Agriculture, Kyrdemkulai, Meghalaya, India (25.74°N, 91.82°E). The site experiences a mid-tropical climate with an average annual rainfall of 2810 mm. Ten genotypes of rapeseed-mustard ( Brassica juncea and B. rapa ) were evaluated: NRCHB 101, PM 25, PM 26, IC 491023, RB 81, RGN 385, DRMR 150 − 35, BPM 11, YST 151, and YSH 401. Seeds were sown in plastic pots (three seeds per pot) filled with a mixture of soil, coco peat, and farmyard manure (2:1). Plants were maintained under polyhouse conditions and irrigated regularly. At the 4–6 leaf stage, each plant was infested with 20 apterous Lipaphis erysimi individuals using a camel hair brush. Inoculated plants were individually enclosed in fine mesh nets to prevent aphid escape and ensure isolation. Observation of aphids Aphid population counts were recorded at three crop stages: flower initiation, full flowering, and silique formation. The number of aphids per 10 cm terminal shoot was counted visually. Resistance was assessed using the Aphid Infestation Index (AII) based on a 0–5 visual grading scale (Bakhetia and Sandhu, 1973 ) (Table 1 ). The index was calculated as: Table 1 Categorization of different rapeseed-mustard varieties on the basis of aphid infestation index Grade no. Description Number of aphids per 10 cm of central shoot 0 Free from aphid infestation. Plants showing excellent growth. 0 1 Normal growth, no curling or yellowing of the leaves, except only a few aphids along with little or no symptoms of injury. 1–20 2 Average growth, curling and yellowing of a few leaves. 20–100 3 Growth below average, curling and yellowing of the leaves. 100–150 4 Very poor growth, heavy curling and yellowing of leaves. Heavy aphid colonies on plants. 150–200 5 Heavy stunting of plants; curling, crinkling and yellowing of almost all the leaves. Plants full of aphids. > 200 $$\:\text{A}\text{p}\text{h}\text{i}\text{d}\:\text{i}\text{n}\text{f}\text{e}\text{s}\text{t}\text{a}\text{t}\text{i}\text{o}\text{n}\:\text{i}\text{n}\text{d}\text{e}\text{x}\:=\frac{0\text{N}+1\text{N}+2\text{N}+3\text{N}+4\text{N}+5\text{N}}{total\:no.of\:plant\:observed\:}$$ Where, N = Number of plants showing respective aphid index Genotypes were categorized into resistance classes following Lal et al. ( 1997 ) (Table 2 ) Table 2 Scales for grading resistance categories against mustard aphid Category Scale Grade of resistance/susceptibility Reaction I 0.0–1.0 Highly resistant HR II 1.1-2.0 Resistant R III 2.1-3.0 Moderately resistant MR IV 3.1-4.0 Susceptible S V 4.1-5.0 Highly susceptible HS Aphid Multiplication Rate To evaluate aphid reproduction, the total aphid count per plant was recorded 15 days post-infestation. Aphid multiplication rate (AMR) was calculated using this formula, as proposed Dhillon et al. ( 2018 ). $$\:\text{A}\text{p}\text{h}\text{i}\text{d}\:\text{m}\text{u}\text{l}\text{t}\text{i}\text{p}\text{l}\text{i}\text{c}\text{a}\text{t}\text{i}\text{o}\text{n}\:\text{r}\text{a}\text{t}\text{e}\left(\text{A}\text{M}\text{R}\right)\:=\:\frac{total\:no.\:\:of\:aphids\:}{number\:of\:aphids\:released\:}\:$$ $$\:\text{D}\text{a}\text{i}\text{l}\text{y}\:\text{m}\text{u}\text{l}\text{t}\text{i}\text{p}\text{l}\text{i}\text{c}\text{a}\text{t}\text{i}\text{o}\text{n}\:\text{r}\text{a}\text{t}\text{e}\:\text{p}\text{e}\text{r}\:\text{a}\text{p}\text{h}\text{i}\text{d}\:=\:\frac{\text{A}\text{p}\text{h}\text{i}\text{d}\:\text{m}\text{u}\text{l}\text{t}\text{i}\text{p}\text{l}\text{i}\text{c}\text{a}\text{t}\text{i}\text{o}\text{n}\:\text{r}\text{a}\text{t}\text{e}}{15}$$ Percentage of Infested Siliques At the silique stage, the total number of siliques per plant and the number infested with aphids were recorded. The percentage of infested siliques was calculated as: $$\:\%\:aphid\:infested\:\:silique\:=\frac{no.\:of\:aphids\:infested\:silique}{total\:no.\:\:of\:silique/plant}\:\times\:100$$ Estimation of Physical Traits Inflorescence and siliques were collected at 70–80 days after sowing from each replication. Samples were oven-dried (70°C, 72 h), powdered, and stored for analysis. Estimation of surface wax by the method of Ebercon et al. ( 1977 ) using colorimetric analysis with potassium dichromate reagent and expressed as % dry weight. Statistical Analysis The experiment was laid out in a completely randomized design (CRD) with three replications. Aphid population data and physical trait values were analyzed using analysis of variance (ANOVA). The Shapiro-Wilk test was applied for normality. Where necessary, square root transformation was performed prior to ANOVA. Duncan’s Multiple Range Test (DMRT) was used for mean separation at p < 0.05. Correlation analyses were conducted between physical traits and aphid parameters (AAII, AMR) using Pearson’s correlation coefficient. All analyses were performed using SPSS software. Results Aphid Population and Infestation Index Significant differences in aphid populations were observed across the ten rapeseed-mustard genotypes at three crop growth stages (flower initiation, full flowering, and silique stage) under protected conditions. PM 25 consistently recorded the lowest aphid population across all stages (73.11 aphids/10 cm central shoot), followed by PM 26 (76.44) and DRMR 150 − 35 (85.78). In contrast, IC 491023 (232.22), YST 151 (196.11), and BPM 11 (188.11) showed the highest aphid counts (Table 3 ). Table 3 Evaluation of rapeseed-mustard genotypes for resistance against mustard aphid under protected condition mean no. of aphids/ 10 cm central shoot Genotypes Flower Initiation stage Full Flowering stage silique stage Overall mean no. of aphids NRCHB 101 94.67 ± 5.51 132.67 ± 7.51 148.67 ± 1.53 125.33 PM 25 49.00 ± 5.00 72.33 ± 7.51 98.00 ± 2.00 73.11 PM 26 74.33 ± 9.02 93.67 ± 7.09 61.33 ± 7.09 76.44 IC 491023 208.33 ± 7.02 256.33 ± 11.02 232.00 ± 7.00 232.22 RB 81 141.33 ± 7.09 186.33 ± 10.07 218.67 ± 15.82 182.11 RGN 385 96.33 ± 1.53 122.00 ± 5.00 140.00 ± 8.00 119.44 DRMR 150 − 35 69.67 ± 5.69 94.67 ± 4.51 93.00 ± 4.58 85.78 BPM 11 143.33 ± 3.06 198.00 ± 2.00 223.00 ± 6.56 188.11 YST 151 157.33 ± 6.81 190.67 ± 6.03 240.33 ± 10.02 196.11 YSH 401 125.33 ± 6.51 137.33 ± 5.69 144.00 ± 10.54 135.56 CD 5% 5.482 7.329 10.330 SE m 1.845 2.467 3.477 The Average Aphid Infestation Index (AAII) ranged from 2.00 to 5.00. Genotypes PM 25, PM 26, and DRMR 150 − 35 were classified as resistant (AAII = 2.00), whereas IC 491023 (5.00) and YST 151 (4.33) were highly susceptible. A similar trend was observed in the percentage of aphid-infested siliques, where PM 25 had the lowest incidence (15.33%), followed by PM 26 (19.23%) and DRMR 150 − 35 (22.07%). The highest infestation was recorded in YST 151 (38.07%) and IC 491023 (37.88%). (Table 4 ) Table 4 categorization of rapeseed-mustard genotypes on the basis of overall mean no. of aphids and average aphid infestation index (AAII) Genotypes overall mean no. of aphids / 10 cm central shoot Average aphid infestation index (AAII) Grade of resistance and susceptibility Reaction % of aphid infested silique NRCHB 101 125.33 2.67 Moderately resistant MR 24.08 PM 25 73.11 2.00 Resistant R 15.33 PM 26 76.44 2.00 Resistant R 19.23 IC 491023 232.22 5.00 Highly susceptible HS 33.05 RB 81 182.11 4.00 Susceptible S 37.88 RGN 385 119.44 2.67 Moderately resistant MR 23.62 DRMR 150 − 35 85.78 2.00 Resistant R 22.07 BPM 11 188.11 4.00 Susceptible S 30.08 YST 151 196.11 4.33 Highly susceptible HS 38.07 YSH 401 135.56 3.00 Moderately resistant MR 25.56 Aphid Multiplication Rate The total number of aphids per plant and the aphid multiplication rate (AMR) also varied significantly among the genotypes. PM 25, PM 26, and DRMR 150 − 35 recorded the lowest AMR values (19.28, 16.73, and 14.70 nymphs/female/generation, respectively), reflecting poor suitability for aphid reproduction. In contrast, BPM 11 (31.87), YST 151 (26.68), and IC 491023 (25.68) exhibited significantly higher multiplication rates, suggesting greater vulnerability to aphid colonization and reproduction (Table 5 ). Table 5 Multiplication of mustard aphid on different rapeseed-mustard genotypes under protected condition Genotypes Aphid population (total no. of aphids/plant) Aphid multiplication rate (nymph/female/generation) Daily multiplication rate (nymphs/female) NRCHB 101 430.67 ± 10.07 de 21.53 ± 0.50 1.44 ± 0.03 PM 25 385.67 ± 20.65 c 19.28 ± 1.03 1.29 ± 0.07 PM 26 334.67 ± 8.39 b 16.73 ± 0.42 1.12 ± 0.03 IC 491023 513.67 ± 6.66 g 25.68 ± 0.33 1.71 ± 0.02 RB 81 474.00 ± 7.21 f 23.70 ± 0.36 1.58 ± 0.02 RGN 385 435.33 ± 21.94 e 21.77 ± 1.10 1.45 ± 0.07 DRMR 150 − 35 294.00 ± 5.29 a 14.70 ± 0.26 0.98 ± 0.02 BPM 11 637.33 ± 15.14 h 31.87 ± 0.76 2.12 ± 0.05 YST 151 533.67 ± 19.86 g 26.68 ± 0.99 1.78 ± 0.07 YSH 401 407.33 ± 7.51 cd 20.37 ± 0.38 1.36 ± 0.03 C.D (p = 0.05) 27.983 0.070 - SEm (±) 9.418 0.024 - Data represented by alphabet are calculated by DMRT Surface Wax Content Significant differences in surface wax content were observed among genotypes in both inflorescence and siliques. PM 25 showed the highest mean surface wax (7.30%), followed by PM 26 (6.76%) and DRMR 150 − 35 (6.75%), while the lowest levels were found in YST 151 (3.49%) and IC 491023 (3.50%) (Table 6 ). Table 6 Estimation of surface wax content in inflorescence and silique of rapeseed-mustard genotypes in relation to average aphid infestation index Genotypes Surface wax (%) Inflorescence Silique Mean (Inflorescence + Silique) NRCHB 101 3.85 ± 1.09 abc 6.34 ± 0.52 bc 5.09 PM 25 6.26 ± 1.93 d 8.34 ± 0.48 d 7.30 PM 26 5.57 ± 0.93 cd 7.95 ± 0.09 cd 6.76 IC 491023 2.07 ± 0.13 ab 4.93 ± 0.93 ab 3.50 RB 81 4.47 ± 1.58 cd 7.68 ± 2.14 cd 6.07 RGN 385 3.75 ± 0.95 bc 6.13 ± 1.05 bc 4.94 DRMR 150 − 35 5.09 ± 0.88 d 8.40 ± 1.44 d 6.75 BPM 11 3.32 ± 1.17 ab 4.74 ± 0.13 ab 4.03 YST 151 3.20 ± 0.61 a 3.77 ± 0.08 a 3.49 YSH 401 3.77 ± 1.05 bc 6.28 ± 0.84 bc 5.03 C.D (p = 0.05) 0.184 0.144 - SEm (±) 0.062 0.049 - Correlation coefficient (r) -0.841 ** -0.798 ** -0.830 ** Data represented by alphabet are calculated by DMRT * Significant at 5% ** Significant at 1% A highly significant negative correlation (r = − 0.830; P < 0.01) was recorded between surface wax and average aphid infestation index, suggesting that genotypes with higher epicuticular wax levels exhibited reduced aphid infestation. Similarly, wax content was significantly negatively correlated with aphid multiplication rate (r = − 0.609; P < 0.05), reinforcing the role of surface wax as a key physical barrier contributing to resistance. Discussion Aphid infestation and multiplication The variation in aphid population and multiplication rate among genotypes is attributed to specific host–insect interactions and genetic differences. Insects exhibit preferences based on the suitability of host plant characteristics, including both physical and biochemical factors. The minimum aphid infestation recorded in resistant genotypes such as PM 25, PM 26, and DRMR 150 − 35 can be linked to such mechanisms, while the high infestation in IC 491023 and YST 151 reflects their susceptibility. Similar results were reported by Mandarwal ( 2014 ), Mishra and Singh ( 2019 ), and Kumar et al. ( 2017 ), who observed genotype-specific responses to aphid attack, with highly resistant genotypes harboring significantly fewer aphids across growth stages. Sreedhar et al . (2019) and Vijay et al. ( 2019 ) also observed that aphid infestation varies developmentally, with some genotypes showing resistance at early stages but becoming susceptible later. The aphid multiplication rate was lowest in DRMR 150 − 35 (14.70), PM 26 (16.73), and PM 25 (19.28), whereas the highest was recorded in BPM 11 (31.87), YST 151 (26.68), and IC 491023 (25.68), indicating poor suitability of the resistant genotypes for aphid reproduction (Shah et al., 2015 ; Imran & Singh, 2015 ). Surface wax content as a physical barrier A considerable variation in surface wax content among the genotypes was observed, attributable to genetic differences. Wax quantity and composition vary not only among species but also across plant parts. In this study, a clear trend was found as surface wax content increased, aphid infestation decreased. The highest surface wax content was recorded in PM 25 (7.30%), PM 26 (6.76%), and DRMR 150 − 35 (6.75%), while the lowest was found in IC 491023 (3.50%) and YST 151 (3.49%). A significant negative correlation (r = − 0.830*) was found between surface wax content and aphid population, confirming the role of surface wax in reducing aphid infestation. These findings agree with Kumar (2008), who reported that Eruca sativa var. T-27 with higher surface wax (5.72%) experienced reduced aphid colonization compared to susceptible BSH-1 (2.91%). Yadav and Rana ( 2018 ) also observed that high-wax genotypes like RH 8701 (5.2%) experienced lower aphid infestations than low-wax genotypes such as RB 50 (2.62%). Similarly, Kumar et al. ( 2017 ) reported that E. sativa var. T-27 had 3.79% more wax than BSH-1 and correspondingly fewer aphids. These results suggest that surface wax serves as a physical barrier, interfering with aphid mobility and stylet penetration. Conclusions In the present study, substantial variation in aphid infestation and multiplication was observed among the evaluated rapeseed-mustard genotypes, highlighting the importance of host plant characteristics in conferring resistance against Lipaphis erysimi . Among the physical traits examined, surface wax content emerged as a critical factor contributing to resistance. Genotypes PM 25, PM 26, and DRMR 150 − 35 exhibited the lowest aphid population, aphid multiplication rate, and percentage of infested siliques. These genotypes consistently recorded the highest surface wax deposition on inflorescences and siliques, suggesting that epicuticular wax functions as an effective physical barrier, deterring aphid colonization and feeding. In contrast, susceptible genotypes such as IC 491023 and YST 151 showed high aphid infestation levels and the lowest surface wax content, reinforcing the association between reduced wax coverage and increased vulnerability to aphids. The findings of this study emphasize that physical defense traits, particularly surface wax content, play a significant role in the expression of host plant resistance. PM 25, which exhibited the highest surface wax and strongest resistance, may serve as a promising parent line in breeding programs aimed at developing mustard cultivars with durable resistance to L. erysimi . Declarations Author Contribution AJAI R conceptualized and conducted the research experiment, collected and analyzed the data, and wrote the original draft of the manuscript. Ngangom Uma supervised the study, provided methodological and technical guidance, and contributed to manuscript revision. Mougdha Duttaassisted in data collection, statistical analysis, and preparation of tables and figures. All authors reviewed and approved the final manuscript. Acknowledgement The authors acknowledge the help and support provided by the Director, ICAR-Directorate of Rapeseed-Mustard Research, Sewar, Bharatpur, during this study. The authors also extend their sincere thanks to ICAR Research Complex for NEH Region, Umiam, and the College of Post Graduate Studies in Agricultural Sciences, Umiam, for providing the necessary genotypes and research facilities. References Bakhetia, D.R.C. and Sandhu, R.S. (1973). Differential response of Brassica species varieties to the aphid, Lipaphis erysimi (Kalt.) infestation. J. Res. Punjab Agric. Univ., 10(3): 272-279. Basavaraju, B.S., Gopal, R.B.K., Raja Gopal, D., and Sheriff, R.A. (1994). Biology of mustard aphid in South India. Mysore J. Agric. Sci., 28(2): 132-134. Bennett, R.N., and Wallsgrove, R.M. (1994). Secondary metabolites in plant defence mechanisms. New Phytol., 127: 617. Dhillon, M.K., Singh, N., Tanwar, A.K., Yadava, D.K. and Vasudeva, S. (2018). Standardization of screening techniques for resistance to Lipaphis erysimi (Kalt.) in rapeseed-mustard under field conditions. Indian J. Exp. Biol., 56: 674–685. Ebercon, A., Blum, A. and Jordan, W.R. (1977). A rapid colorimetric method for epicuticular wax content of sorghum leaves. Crop Sci., 17: 179–180. Imran, A. and Singh, S.P. (2015). Growth and development behaviour of Lipaphis erysimi (Kalt.) at leaf and flowering stage on different mustard genotypes. Ann. Biol., 31(2): 251–256. Kumar, A., Sharma, P., Thomas, L., Agnihotri, A. and Banga, S.S. (2009). Canola cultivation in India: scenario and future strategy. 16th Australian Res. Assembly on Brassicas, Ballarat, Victoria: 1–5. Kumar, S., Singh, Y.P., Singh, S.P., and Singh, R. (2017). Physical and biochemical aspects of host plant resistance to mustard aphid, Lipaphis erysimi (Kaltenbach) in rapeseed-mustard. Arthropod-Plant Interact., 11(4): 551–559. Kumrawat, M. and Yadav, M. (2018). Trends in area, production, and yield of mustard crop in Bharatpur region of Rajasthan. Int. J. Eng. Dev. Res., 6: 315–321. Lal, M.N., Singh, S.S. and Singh, V.P. (1997). Screening of Brassica germplasms for resistance against mustard aphid, Lipaphis erysimi (Kalt.). J. Entomol. Res., 21(4): 371–375. Mandal, D., Bhowmik, P., and Chatterjee, M.L. (2012). Evaluation of new and conventional insecticides for the management of mustard aphid, Lipaphis erysimi (Kalt.) (Homoptera: Aphididae) on rapeseed mustard (Brassica juncea L.). J. Plant Prot. Sci., 4(2): 37–42. Mandarwal, N. (2014). Management of aphid, Lipaphis erysimi (Kalt.) on mustard (Brassica juncea (Linn.) Czern and Coss) in semi-arid region of Rajasthan. M.Sc. Thesis, SKK College of Agriculture, Jobner. 70–71 p. Mishra, V.K. and Singh, N.N. (2019). Evaluation of glucosinolate in different varieties/lines against mustard aphid, Lipaphis erysimi (Kalt.) on mustard crop. J. Appl. Zool. Res., 30(1): 64–68. Mishra, V.K., and Singh, N.N. (2019). Efficacy of insecticides against mustard aphid Lipaphis erysimi. Indian J. Entomol., 81(2): 343–347. Painter, R.H. (1951). Insect Resistance in Crop Plants. The University Press of Kansas, Lawrence and London. Samal, I., Dhillon, M.K., and Singh, N. (2021). Biological performance and biochemical interactions of mustard aphid (Lipaphis erysimi) in Brassica juncea. Indian J. Agric. Sci., 91(9): 1347–1352. Sarkar, S., and Kumar, A. (2022). Comparative efficacy & cost-benefit ratio of selected biopesticides and chemicals against mustard aphid, Lipaphis erysimi (Kaltenbach). Pharma Innov. J., 11(7): 4671–4675. Shah, S.R.A., Khan, S.A., Junaid, K., Zaman, S.S.M., Saleem, N. and Adnan, M. (2015). Screening of mustard genotypes for antixenosis and multiplication against mustard aphid, Lipaphis erysimi (Kalt.) (Aphididae: Homoptera). J. Entomol. Zool. Stud., 3(6): 84–87. Shreedhar, B.K., Chakraborty, D., Supriya, O., Hath, T.K. and Sahoo, S.K. (2019). Screening of Indian mustard (Brassica juncea L.) genotypes against mustard aphid, Lipaphis erysimi (Kalt.) under Terai zone of West Bengal. J. Entomol. Zool. Stud., 7(5): 1340–1344. Singh, T.R., Singh, M.P., Singh, K.I., Devi, T.B., and Singh, N.G. (2007). Comparative efficacy of certain neem products and conventional insecticides against Lipaphis erysimi (Kalt.) and their safety to its natural enemies in rapeseed. Indian J. Entomol., 69(3): 259–264. Singh, Y.P., and Sharma, K.C. (2002). Integrated approach to manage the mustard aphid, Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae) in oilseed Brassica crops-A review. J. Amphibiol., 16: 77–78. Smith, C.M., and Boyko, E.V. (2007). The molecular bases of plant resistance and defense responses to aphid feeding: current status. Entomol. Exp. Appl., 122(1): 1-16. Stadler, B., and Dixon, A.F.G. (2005). Ecology and evolution of aphid-ant interactions. Annu. Rev. Ecol. Evol. Syst., 36: 345-372. Vijay, K.M., Singh, N.N., and Sambhrant, K. (2019). Reliable screening technique for resistance traits against mustard aphid, Lipaphis erysimi (Kalt.) under field conditions. J. Entomol. Res., 43: 974. Yadav, M., and Rana, J.S. (2018). Biochemical constituent of Brassica juncea genotypes in relation to mustard aphid (Lipaphis erysimi Kalt.) infestation. J. Pharmacogn. Phytochem., 7(2): 938-943. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Dec, 2025 Read the published version in Arthropod-Plant Interactions → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7303385","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":500019181,"identity":"c231deac-ef6b-4b6d-acd4-ef4a5e7f5318","order_by":0,"name":"Ajai R rangesan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIie2PMarCQBCG18Y0A9tOeEGvMHYWgXcVq1R5YGWtlYXrAcRLCF5gZME0sRQSbJ6NNgrapUjhrgdIthTcb2H4F+ZjZoTweD4SNg8QZDA1Hxo6K3EUKrYKOo9KYipGNjgocqbPXEUawtX1uKnGKOR8MWpUkPe0U6BB/qSTUpnFMD9smscwE4NRwnWaFGAUwr9mpc/ZY1cbhco8KWsXhTgnDZAAFcH+5DRlwPlYRxBDqNLuKSKE1lt6RbZ93hX+yiC7lLc67sn5suV8ZCE6yiagd21ut8ipKZVNwX97t8fj8XwlL/LQToNx6FKhAAAAAElFTkSuQmCC","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Ajai","middleName":"R","lastName":"rangesan","suffix":""},{"id":500019183,"identity":"cde8240e-b5dd-4408-ba54-fbea7e3cdc77","order_by":1,"name":"Ngangom Uma Devi","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ngangom","middleName":"Uma","lastName":"Devi","suffix":""},{"id":500019184,"identity":"5574fb06-70a5-42b2-9b38-d46de8b1c930","order_by":2,"name":"Mougdha Dutta","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Mougdha","middleName":"","lastName":"Dutta","suffix":""}],"badges":[],"createdAt":"2025-08-05 18:38:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7303385/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7303385/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11829-025-10209-2","type":"published","date":"2025-12-05T15:58:16+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":89459848,"identity":"09150fdf-99f0-4e5e-be1b-16628cf5b45e","added_by":"auto","created_at":"2025-08-20 07:40:25","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":66668,"visible":true,"origin":"","legend":"\u003cp\u003eAphid population per 10 cm central shoot at different stage under protected condition\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7303385/v1/45d11d6d712df26b4e923d82.png"},{"id":89459851,"identity":"5de29fdb-6e32-4768-aaed-ae2c82b4ff45","added_by":"auto","created_at":"2025-08-20 07:40:25","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":64780,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of Surface wax content in relation to Average aphid infestation index\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7303385/v1/510cfe477f93d86dad0d1701.png"},{"id":97724113,"identity":"5d6337e8-c3e7-4a67-b234-dbb97368b5a3","added_by":"auto","created_at":"2025-12-08 16:12:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1013391,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7303385/v1/dffc7081-9b18-4b42-98be-cdef49567393.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Physical basis of host plant resistance in rapeseed and mustard against mustard aphid, Lipaphis erysimi (Kaltenbach)","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRapeseed-mustard (\u003cem\u003eBrassica\u003c/em\u003e spp.) is among the most important oilseed crops in India, contributing approximately 20\u0026ndash;22% to the country's total oilseed production (Kumrawat \u0026amp; Yadav, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). However, its productivity is severely constrained by the mustard aphid, \u003cem\u003eLipaphis erysimi\u003c/em\u003e (Kaltenbach) (Hemiptera: Aphididae), a destructive pest that causes yield losses ranging from 9\u0026ndash;96%, depending on the crop stage and infestation severity (Mandal et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). This aphid damages the crop by feeding on phloem sap, reducing seed set and oil content, and excreting honeydew that promotes sooty mould, thereby interfering with photosynthesis (Mandal et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). In addition, it serves as a vector of several plant viruses (Banerjee \u003cem\u003eet al\u003c/em\u003e., 2004).\u003c/p\u003e\u003cp\u003e\u003cem\u003eL. erysimi\u003c/em\u003e exhibits parthenogenetic and viviparous reproduction, completing up to 45 generations per year under favorable conditions (Basavaraju et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e1994\u003c/span\u003e). Its rapid multiplication and mobility complicate effective chemical control. Although systemic insecticides such as imidacloprid and dimethoate are commonly used (Singh et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Mishra \u0026amp; Singh, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), over-reliance has led to the development of resistance, pest resurgence, environmental hazards, and negative impacts on beneficial insects (Singh \u0026amp; Sharma, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Sarkar \u0026amp; Kumar, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eHost plant resistance offers a sustainable, ecologically sound approach to pest management. Resistance mechanisms can be morphological or biochemical, including antixenosis, antibiosis, and tolerance (Painter, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e1951\u003c/span\u003e; Stadler \u0026amp; Dixon, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Physical traits-such as trichome density, cuticle thickness, and surface wax-act as the first line of defense, influencing aphid landing, probing, and feeding behavior (Bennett \u0026amp; Wallsgrove, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; Smith \u0026amp; Boyko, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). In particular, epicuticular waxes have been shown to interfere with aphid colonization and are negatively correlated with infestation levels (Samal et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Considering these factors, the present study was undertaken to evaluate the physical traits contributing to resistance in selected rapeseed-mustard genotypes against \u003cem\u003eL. erysimi\u003c/em\u003e under protected conditions.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eThe study was conducted during the 2024\u0026ndash;25 growing season under controlled conditions at the Polyhouse facility of the College of Agriculture, Kyrdemkulai, Meghalaya, India (25.74\u0026deg;N, 91.82\u0026deg;E). The site experiences a mid-tropical climate with an average annual rainfall of 2810 mm.\u003c/p\u003e\u003cp\u003eTen genotypes of rapeseed-mustard (\u003cem\u003eBrassica juncea\u003c/em\u003e and \u003cem\u003eB. rapa\u003c/em\u003e) were evaluated: NRCHB 101, PM 25, PM 26, IC 491023, RB 81, RGN 385, DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35, BPM 11, YST 151, and YSH 401. Seeds were sown in plastic pots (three seeds per pot) filled with a mixture of soil, coco peat, and farmyard manure (2:1). Plants were maintained under polyhouse conditions and irrigated regularly. At the 4\u0026ndash;6 leaf stage, each plant was infested with 20 apterous \u003cem\u003eLipaphis erysimi\u003c/em\u003e individuals using a camel hair brush. Inoculated plants were individually enclosed in fine mesh nets to prevent aphid escape and ensure isolation.\u003c/p\u003e\u003cp\u003e\u003cb\u003eObservation of aphids\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAphid population counts were recorded at three crop stages: flower initiation, full flowering, and silique formation. The number of aphids per 10 cm terminal shoot was counted visually.\u003c/p\u003e\u003cp\u003eResistance was assessed using the Aphid Infestation Index (AII) based on a 0\u0026ndash;5 visual grading scale (Bakhetia and Sandhu, \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1973\u003c/span\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The index was calculated as:\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\u003eCategorization of different rapeseed-mustard varieties on the basis of aphid infestation index\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGrade no.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDescription\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNumber of aphids per 10 cm of central shoot\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFree from aphid infestation. Plants showing excellent growth.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\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\u003eNormal growth, no curling or yellowing of the leaves, except only a few aphids along with little or no symptoms of injury.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u0026ndash;20\u003c/p\u003e\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\u003eAverage growth, curling and yellowing of a few leaves.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20\u0026ndash;100\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGrowth below average, curling and yellowing of the leaves.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e100\u0026ndash;150\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVery poor growth, heavy curling and yellowing of leaves. Heavy aphid colonies on plants.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e150\u0026ndash;200\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHeavy stunting of plants; curling, crinkling and yellowing of almost all the leaves. Plants full of aphids.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;200\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\text{A}\\text{p}\\text{h}\\text{i}\\text{d}\\:\\text{i}\\text{n}\\text{f}\\text{e}\\text{s}\\text{t}\\text{a}\\text{t}\\text{i}\\text{o}\\text{n}\\:\\text{i}\\text{n}\\text{d}\\text{e}\\text{x}\\:=\\frac{0\\text{N}+1\\text{N}+2\\text{N}+3\\text{N}+4\\text{N}+5\\text{N}}{total\\:no.of\\:plant\\:observed\\:}$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eWhere, N\u0026thinsp;=\u0026thinsp;Number of plants showing respective aphid index\u003c/p\u003e\u003cp\u003eGenotypes were categorized into resistance classes following Lal et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1997\u003c/span\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\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\u003eScales for grading resistance categories against mustard aphid\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" 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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCategory\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eScale\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGrade of resistance/susceptibility\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eReaction\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.0\u0026ndash;1.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHighly resistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHR\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.1-2.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2.1-3.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerately resistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMR\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3.1-4.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4.1-5.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHighly susceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHS\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\u003cb\u003eAphid Multiplication Rate\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTo evaluate aphid reproduction, the total aphid count per plant was recorded 15 days post-infestation. Aphid multiplication rate (AMR) was calculated using this formula, as proposed Dhillon et al. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:\\text{A}\\text{p}\\text{h}\\text{i}\\text{d}\\:\\text{m}\\text{u}\\text{l}\\text{t}\\text{i}\\text{p}\\text{l}\\text{i}\\text{c}\\text{a}\\text{t}\\text{i}\\text{o}\\text{n}\\:\\text{r}\\text{a}\\text{t}\\text{e}\\left(\\text{A}\\text{M}\\text{R}\\right)\\:=\\:\\frac{total\\:no.\\:\\:of\\:aphids\\:}{number\\:of\\:aphids\\:released\\:}\\:$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e\n$$\\:\\text{D}\\text{a}\\text{i}\\text{l}\\text{y}\\:\\text{m}\\text{u}\\text{l}\\text{t}\\text{i}\\text{p}\\text{l}\\text{i}\\text{c}\\text{a}\\text{t}\\text{i}\\text{o}\\text{n}\\:\\text{r}\\text{a}\\text{t}\\text{e}\\:\\text{p}\\text{e}\\text{r}\\:\\text{a}\\text{p}\\text{h}\\text{i}\\text{d}\\:=\\:\\frac{\\text{A}\\text{p}\\text{h}\\text{i}\\text{d}\\:\\text{m}\\text{u}\\text{l}\\text{t}\\text{i}\\text{p}\\text{l}\\text{i}\\text{c}\\text{a}\\text{t}\\text{i}\\text{o}\\text{n}\\:\\text{r}\\text{a}\\text{t}\\text{e}}{15}$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePercentage of Infested Siliques\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAt the silique stage, the total number of siliques per plant and the number infested with aphids were recorded. The percentage of infested siliques was calculated as:\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e\n$$\\:\\%\\:aphid\\:infested\\:\\:silique\\:=\\frac{no.\\:of\\:aphids\\:infested\\:silique}{total\\:no.\\:\\:of\\:silique/plant}\\:\\times\\:100$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eEstimation of Physical Traits\u003c/b\u003e\u003c/p\u003e\u003cp\u003eInflorescence and siliques were collected at 70\u0026ndash;80 days after sowing from each replication. Samples were oven-dried (70\u0026deg;C, 72 h), powdered, and stored for analysis. Estimation of surface wax by the method of Ebercon et al. (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1977\u003c/span\u003e) using colorimetric analysis with potassium dichromate reagent and expressed as % dry weight.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eThe experiment was laid out in a completely randomized design (CRD) with three replications. Aphid population data and physical trait values were analyzed using analysis of variance (ANOVA). The Shapiro-Wilk test was applied for normality. Where necessary, square root transformation was performed prior to ANOVA. Duncan\u0026rsquo;s Multiple Range Test (DMRT) was used for mean separation at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Correlation analyses were conducted between physical traits and aphid parameters (AAII, AMR) using Pearson\u0026rsquo;s correlation coefficient. All analyses were performed using SPSS software.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cb\u003eAphid Population and Infestation Index\u003c/b\u003e\u003c/p\u003e\u003cp\u003eSignificant differences in aphid populations were observed across the ten rapeseed-mustard genotypes at three crop growth stages (flower initiation, full flowering, and silique stage) under protected conditions. PM 25 consistently recorded the lowest aphid population across all stages (73.11 aphids/10 cm central shoot), followed by PM 26 (76.44) and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 (85.78). In contrast, IC 491023 (232.22), YST 151 (196.11), and BPM 11 (188.11) showed the highest aphid counts (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\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\u003eEvaluation of rapeseed-mustard genotypes for resistance against mustard aphid under protected condition\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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u003cp\u003emean no. of aphids/ 10 cm central shoot\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGenotypes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFlower Initiation stage\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eFull Flowering stage\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003esilique stage\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eOverall mean no. of aphids\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNRCHB 101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e94.67\u0026thinsp;\u0026plusmn;\u0026thinsp;5.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e132.67\u0026thinsp;\u0026plusmn;\u0026thinsp;7.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e148.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e125.33\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e49.00\u0026thinsp;\u0026plusmn;\u0026thinsp;5.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e72.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e98.00\u0026thinsp;\u0026plusmn;\u0026thinsp;2.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e73.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e74.33\u0026thinsp;\u0026plusmn;\u0026thinsp;9.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e93.67\u0026thinsp;\u0026plusmn;\u0026thinsp;7.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e61.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e76.44\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIC 491023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e208.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e256.33\u0026thinsp;\u0026plusmn;\u0026thinsp;11.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e232.00\u0026thinsp;\u0026plusmn;\u0026thinsp;7.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e232.22\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRB 81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e141.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e186.33\u0026thinsp;\u0026plusmn;\u0026thinsp;10.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e218.67\u0026thinsp;\u0026plusmn;\u0026thinsp;15.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e182.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRGN 385\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e96.33\u0026thinsp;\u0026plusmn;\u0026thinsp;1.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e122.00\u0026thinsp;\u0026plusmn;\u0026thinsp;5.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e140.00\u0026thinsp;\u0026plusmn;\u0026thinsp;8.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e119.44\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e69.67\u0026thinsp;\u0026plusmn;\u0026thinsp;5.69\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94.67\u0026thinsp;\u0026plusmn;\u0026thinsp;4.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e93.00\u0026thinsp;\u0026plusmn;\u0026thinsp;4.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e85.78\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBPM 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e143.33\u0026thinsp;\u0026plusmn;\u0026thinsp;3.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e198.00\u0026thinsp;\u0026plusmn;\u0026thinsp;2.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e223.00\u0026thinsp;\u0026plusmn;\u0026thinsp;6.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e188.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYST 151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e157.33\u0026thinsp;\u0026plusmn;\u0026thinsp;6.81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e190.67\u0026thinsp;\u0026plusmn;\u0026thinsp;6.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e240.33\u0026thinsp;\u0026plusmn;\u0026thinsp;10.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e196.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYSH 401\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e125.33\u0026thinsp;\u0026plusmn;\u0026thinsp;6.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e137.33\u0026thinsp;\u0026plusmn;\u0026thinsp;5.69\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e144.00\u0026thinsp;\u0026plusmn;\u0026thinsp;10.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e135.56\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCD 5%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.482\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.329\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10.330\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\u003eSE m\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.845\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.467\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.477\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe Average Aphid Infestation Index (AAII) ranged from 2.00 to 5.00. Genotypes PM 25, PM 26, and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 were classified as resistant (AAII\u0026thinsp;=\u0026thinsp;2.00), whereas IC 491023 (5.00) and YST 151 (4.33) were highly susceptible. A similar trend was observed in the percentage of aphid-infested siliques, where PM 25 had the lowest incidence (15.33%), followed by PM 26 (19.23%) and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 (22.07%). The highest infestation was recorded in YST 151 (38.07%) and IC 491023 (37.88%). (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e)\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\u003ecategorization of rapeseed-mustard genotypes on the basis of overall mean no. of aphids and average aphid infestation index (AAII)\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=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGenotypes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eoverall mean no. of aphids / 10 cm central shoot\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAverage aphid infestation index (AAII)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGrade of resistance and susceptibility\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eReaction\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e% of aphid infested silique\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNRCHB 101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e125.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerately resistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e24.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e73.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e15.33\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e76.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e19.23\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIC 491023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e232.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHighly susceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e33.05\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRB 81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e182.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e37.88\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRGN 385\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e119.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerately resistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e23.62\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e85.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e22.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBPM 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e188.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e30.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYST 151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e196.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHighly susceptible\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e38.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYSH 401\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e135.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerately resistant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e25.56\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\u003cb\u003eAphid Multiplication Rate\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe total number of aphids per plant and the aphid multiplication rate (AMR) also varied significantly among the genotypes. PM 25, PM 26, and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 recorded the lowest AMR values (19.28, 16.73, and 14.70 nymphs/female/generation, respectively), reflecting poor suitability for aphid reproduction. In contrast, BPM 11 (31.87), YST 151 (26.68), and IC 491023 (25.68) exhibited significantly higher multiplication rates, suggesting greater vulnerability to aphid colonization and reproduction (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\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\u003eMultiplication of mustard aphid on different rapeseed-mustard genotypes under protected condition\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGenotypes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAphid population (total no. of aphids/plant)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAphid multiplication rate (nymph/female/generation)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eDaily multiplication rate (nymphs/female)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNRCHB 101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e430.67\u0026thinsp;\u0026plusmn;\u0026thinsp;10.07\u003csup\u003ede\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e21.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e385.67\u0026thinsp;\u0026plusmn;\u0026thinsp;20.65\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.28\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e334.67\u0026thinsp;\u0026plusmn;\u0026thinsp;8.39\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIC 491023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e513.67\u0026thinsp;\u0026plusmn;\u0026thinsp;6.66\u003csup\u003eg\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRB 81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e474.00\u0026thinsp;\u0026plusmn;\u0026thinsp;7.21\u003csup\u003ef\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRGN 385\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e435.33\u0026thinsp;\u0026plusmn;\u0026thinsp;21.94\u003csup\u003ee\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e21.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e294.00\u0026thinsp;\u0026plusmn;\u0026thinsp;5.29\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBPM 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e637.33\u0026thinsp;\u0026plusmn;\u0026thinsp;15.14\u003csup\u003eh\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYST 151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e533.67\u0026thinsp;\u0026plusmn;\u0026thinsp;19.86\u003csup\u003eg\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.78\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYSH 401\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e407.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.51\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC.D (p\u0026thinsp;=\u0026thinsp;0.05)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27.983\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.070\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSEm (\u0026plusmn;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.418\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eData represented by alphabet are calculated by DMRT\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eSurface Wax Content\u003c/b\u003e\u003c/p\u003e\u003cp\u003eSignificant differences in surface wax content were observed among genotypes in both inflorescence and siliques. PM 25 showed the highest mean surface wax (7.30%), followed by PM 26 (6.76%) and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 (6.75%), while the lowest levels were found in YST 151 (3.49%) and IC 491023 (3.50%) (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e).\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 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eEstimation of surface wax content in inflorescence and silique of rapeseed-mustard genotypes in relation to average aphid infestation index\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGenotypes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u003cp\u003eSurface wax (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eInflorescence\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSilique\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMean (Inflorescence\u0026thinsp;+\u0026thinsp;Silique)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNRCHB 101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.09\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.09\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.26\u0026thinsp;\u0026plusmn;\u0026thinsp;1.93\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7.30\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePM 26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.76\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIC 491023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRB 81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.47\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.68\u0026thinsp;\u0026plusmn;\u0026thinsp;2.14\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRGN 385\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4.94\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBPM 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.32\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYST 151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.49\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYSH 401\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC.D (p\u0026thinsp;=\u0026thinsp;0.05)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.184\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.144\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSEm (\u0026plusmn;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.062\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.049\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCorrelation coefficient (r)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-0.841\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.798\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.830\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eData represented by alphabet are calculated by DMRT\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e* Significant at 5%\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e** Significant at 1%\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eA highly significant negative correlation (r = \u0026minus;\u0026thinsp;0.830; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) was recorded between surface wax and average aphid infestation index, suggesting that genotypes with higher epicuticular wax levels exhibited reduced aphid infestation. Similarly, wax content was significantly negatively correlated with aphid multiplication rate (r = \u0026minus;\u0026thinsp;0.609; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), reinforcing the role of surface wax as a key physical barrier contributing to resistance.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e\u003cb\u003eAphid infestation and multiplication\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe variation in aphid population and multiplication rate among genotypes is attributed to specific host\u0026ndash;insect interactions and genetic differences. Insects exhibit preferences based on the suitability of host plant characteristics, including both physical and biochemical factors. The minimum aphid infestation recorded in resistant genotypes such as PM 25, PM 26, and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 can be linked to such mechanisms, while the high infestation in IC 491023 and YST 151 reflects their susceptibility.\u003c/p\u003e\u003cp\u003eSimilar results were reported by Mandarwal (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), Mishra and Singh (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), and Kumar et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), who observed genotype-specific responses to aphid attack, with highly resistant genotypes harboring significantly fewer aphids across growth stages. Sreedhar \u003cem\u003eet al\u003c/em\u003e. (2019) and Vijay et al. (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) also observed that aphid infestation varies developmentally, with some genotypes showing resistance at early stages but becoming susceptible later. The aphid multiplication rate was lowest in DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 (14.70), PM 26 (16.73), and PM 25 (19.28), whereas the highest was recorded in BPM 11 (31.87), YST 151 (26.68), and IC 491023 (25.68), indicating poor suitability of the resistant genotypes for aphid reproduction (Shah et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Imran \u0026amp; Singh, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eSurface wax content as a physical barrier\u003c/b\u003e\u003c/p\u003e\u003cp\u003eA considerable variation in surface wax content among the genotypes was observed, attributable to genetic differences. Wax quantity and composition vary not only among species but also across plant parts. In this study, a clear trend was found as surface wax content increased, aphid infestation decreased.\u003c/p\u003e\u003cp\u003eThe highest surface wax content was recorded in PM 25 (7.30%), PM 26 (6.76%), and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 (6.75%), while the lowest was found in IC 491023 (3.50%) and YST 151 (3.49%). A significant negative correlation (r = \u0026minus;\u0026thinsp;0.830*) was found between surface wax content and aphid population, confirming the role of surface wax in reducing aphid infestation. These findings agree with Kumar (2008), who reported that \u003cem\u003eEruca sativa\u003c/em\u003e var. T-27 with higher surface wax (5.72%) experienced reduced aphid colonization compared to susceptible BSH-1 (2.91%).\u003c/p\u003e\u003cp\u003eYadav and Rana (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) also observed that high-wax genotypes like RH 8701 (5.2%) experienced lower aphid infestations than low-wax genotypes such as RB 50 (2.62%). Similarly, Kumar et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) reported that \u003cem\u003eE. sativa\u003c/em\u003e var. T-27 had 3.79% more wax than BSH-1 and correspondingly fewer aphids. These results suggest that surface wax serves as a physical barrier, interfering with aphid mobility and stylet penetration.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn the present study, substantial variation in aphid infestation and multiplication was observed among the evaluated rapeseed-mustard genotypes, highlighting the importance of host plant characteristics in conferring resistance against \u003cem\u003eLipaphis erysimi\u003c/em\u003e. Among the physical traits examined, surface wax content emerged as a critical factor contributing to resistance.\u003c/p\u003e\u003cp\u003eGenotypes PM 25, PM 26, and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 exhibited the lowest aphid population, aphid multiplication rate, and percentage of infested siliques. These genotypes consistently recorded the highest surface wax deposition on inflorescences and siliques, suggesting that epicuticular wax functions as an effective physical barrier, deterring aphid colonization and feeding.\u003c/p\u003e\u003cp\u003eIn contrast, susceptible genotypes such as IC 491023 and YST 151 showed high aphid infestation levels and the lowest surface wax content, reinforcing the association between reduced wax coverage and increased vulnerability to aphids.\u003c/p\u003e\u003cp\u003eThe findings of this study emphasize that physical defense traits, particularly surface wax content, play a significant role in the expression of host plant resistance. PM 25, which exhibited the highest surface wax and strongest resistance, may serve as a promising parent line in breeding programs aimed at developing mustard cultivars with durable resistance to \u003cem\u003eL. erysimi\u003c/em\u003e.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAJAI R conceptualized and conducted the research experiment, collected and analyzed the data, and wrote the original draft of the manuscript. Ngangom Uma supervised the study, provided methodological and technical guidance, and contributed to manuscript revision. Mougdha Duttaassisted in data collection, statistical analysis, and preparation of tables and figures. All authors reviewed and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors acknowledge the help and support provided by the Director, ICAR-Directorate of Rapeseed-Mustard Research, Sewar, Bharatpur, during this study. The authors also extend their sincere thanks to ICAR Research Complex for NEH Region, Umiam, and the College of Post Graduate Studies in Agricultural Sciences, Umiam, for providing the necessary genotypes and research facilities.\t\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBakhetia, D.R.C. and Sandhu, R.S. (1973). Differential response of Brassica species varieties to the aphid, Lipaphis erysimi (Kalt.) infestation. J. Res. Punjab Agric. Univ., 10(3): 272-279.\u003c/li\u003e\n\u003cli\u003eBasavaraju, B.S., Gopal, R.B.K., Raja Gopal, D., and Sheriff, R.A. (1994). Biology of mustard aphid in South India. Mysore J. Agric. Sci., 28(2): 132-134.\u003c/li\u003e\n\u003cli\u003eBennett, R.N., and Wallsgrove, R.M. (1994). Secondary metabolites in plant defence mechanisms. New Phytol., 127: 617.\u003c/li\u003e\n\u003cli\u003eDhillon, M.K., Singh, N., Tanwar, A.K., Yadava, D.K. and Vasudeva, S. (2018). Standardization of screening techniques for resistance to Lipaphis erysimi (Kalt.) in rapeseed-mustard under field conditions. Indian J. Exp. Biol., 56: 674\u0026ndash;685.\u003c/li\u003e\n\u003cli\u003eEbercon, A., Blum, A. and Jordan, W.R. (1977). A rapid colorimetric method for epicuticular wax content of sorghum leaves. Crop Sci., 17: 179\u0026ndash;180.\u003c/li\u003e\n\u003cli\u003eImran, A. and Singh, S.P. (2015). Growth and development behaviour of Lipaphis erysimi (Kalt.) at leaf and flowering stage on different mustard genotypes. Ann. Biol., 31(2): 251\u0026ndash;256.\u003c/li\u003e\n\u003cli\u003eKumar, A., Sharma, P., Thomas, L., Agnihotri, A. and Banga, S.S. (2009). Canola cultivation in India: scenario and future strategy. 16th Australian Res. Assembly on Brassicas, Ballarat, Victoria: 1\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003eKumar, S., Singh, Y.P., Singh, S.P., and Singh, R. (2017). Physical and biochemical aspects of host plant resistance to mustard aphid, Lipaphis erysimi (Kaltenbach) in rapeseed-mustard. Arthropod-Plant Interact., 11(4): 551\u0026ndash;559.\u003c/li\u003e\n\u003cli\u003eKumrawat, M. and Yadav, M. (2018). Trends in area, production, and yield of mustard crop in Bharatpur region of Rajasthan. Int. J. Eng. Dev. Res., 6: 315\u0026ndash;321.\u003c/li\u003e\n\u003cli\u003eLal, M.N., Singh, S.S. and Singh, V.P. (1997). Screening of Brassica germplasms for resistance against mustard aphid, Lipaphis erysimi (Kalt.). J. Entomol. Res., 21(4): 371\u0026ndash;375.\u003c/li\u003e\n\u003cli\u003eMandal, D., Bhowmik, P., and Chatterjee, M.L. (2012). Evaluation of new and conventional insecticides for the management of mustard aphid, Lipaphis erysimi (Kalt.) (Homoptera: Aphididae) on rapeseed mustard (Brassica juncea L.). J. Plant Prot. Sci., 4(2): 37\u0026ndash;42.\u003c/li\u003e\n\u003cli\u003eMandarwal, N. (2014). Management of aphid, Lipaphis erysimi (Kalt.) on mustard (Brassica juncea (Linn.) Czern and Coss) in semi-arid region of Rajasthan. M.Sc. Thesis, SKK College of Agriculture, Jobner. 70\u0026ndash;71 p.\u003c/li\u003e\n\u003cli\u003eMishra, V.K. and Singh, N.N. (2019). Evaluation of glucosinolate in different varieties/lines against mustard aphid, Lipaphis erysimi (Kalt.) on mustard crop. J. Appl. Zool. Res., 30(1): 64\u0026ndash;68.\u003c/li\u003e\n\u003cli\u003eMishra, V.K., and Singh, N.N. (2019). Efficacy of insecticides against mustard aphid Lipaphis erysimi. Indian J. Entomol., 81(2): 343\u0026ndash;347.\u003c/li\u003e\n\u003cli\u003ePainter, R.H. (1951). Insect Resistance in Crop Plants. The University Press of Kansas, Lawrence and London.\u003c/li\u003e\n\u003cli\u003eSamal, I., Dhillon, M.K., and Singh, N. (2021). Biological performance and biochemical interactions of mustard aphid (Lipaphis erysimi) in Brassica juncea. Indian J. Agric. Sci., 91(9): 1347\u0026ndash;1352.\u003c/li\u003e\n\u003cli\u003eSarkar, S., and Kumar, A. (2022). Comparative efficacy \u0026amp; cost-benefit ratio of selected biopesticides and chemicals against mustard aphid, Lipaphis erysimi (Kaltenbach). Pharma Innov. J., 11(7): 4671\u0026ndash;4675.\u003c/li\u003e\n\u003cli\u003eShah, S.R.A., Khan, S.A., Junaid, K., Zaman, S.S.M., Saleem, N. and Adnan, M. (2015). Screening of mustard genotypes for antixenosis and multiplication against mustard aphid, Lipaphis erysimi (Kalt.) (Aphididae: Homoptera). J. Entomol. Zool. Stud., 3(6): 84\u0026ndash;87.\u003c/li\u003e\n\u003cli\u003eShreedhar, B.K., Chakraborty, D., Supriya, O., Hath, T.K. and Sahoo, S.K. (2019). Screening of Indian mustard (Brassica juncea L.) genotypes against mustard aphid, Lipaphis erysimi (Kalt.) under Terai zone of West Bengal. J. Entomol. Zool. Stud., 7(5): 1340\u0026ndash;1344.\u003c/li\u003e\n\u003cli\u003eSingh, T.R., Singh, M.P., Singh, K.I., Devi, T.B., and Singh, N.G. (2007). Comparative efficacy of certain neem products and conventional insecticides against Lipaphis erysimi (Kalt.) and their safety to its natural enemies in rapeseed. Indian J. Entomol., 69(3): 259\u0026ndash;264.\u003c/li\u003e\n\u003cli\u003eSingh, Y.P., and Sharma, K.C. (2002). Integrated approach to manage the mustard aphid, Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae) in oilseed Brassica crops-A review. J. Amphibiol., 16: 77\u0026ndash;78.\u003c/li\u003e\n\u003cli\u003eSmith, C.M., and Boyko, E.V. (2007). The molecular bases of plant resistance and defense responses to aphid feeding: current status. Entomol. Exp. Appl., 122(1): 1-16.\u003c/li\u003e\n\u003cli\u003eStadler, B., and Dixon, A.F.G. (2005). Ecology and evolution of aphid-ant interactions. Annu. Rev. Ecol. Evol. Syst., 36: 345-372.\u003c/li\u003e\n\u003cli\u003eVijay, K.M., Singh, N.N., and Sambhrant, K. (2019). Reliable screening technique for resistance traits against mustard aphid, Lipaphis erysimi (Kalt.) under field conditions. J. Entomol. Res., 43: 974.\u003c/li\u003e\n\u003cli\u003eYadav, M., and Rana, J.S. (2018). Biochemical constituent of Brassica juncea genotypes in relation to mustard aphid (Lipaphis erysimi Kalt.) infestation. J. Pharmacogn. Phytochem., 7(2): 938-943.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Lipaphis erysimi, Rapeseed-mustard, genotype, Surface wax, Host plant resistance","lastPublishedDoi":"10.21203/rs.3.rs-7303385/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7303385/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRapeseed-mustard (\u003cem\u003eBrassica\u003c/em\u003e spp.) is a vital oilseed crop in India, frequently affected by the mustard aphid, \u003cem\u003eLipaphis erysimi\u003c/em\u003e (Kaltenbach), a major sap-sucking pest that causes substantial yield losses. Considering the drawbacks of chemical control, host plant resistance offers a sustainable alternative. The present study was conducted under protected conditions to assess the physical basis of resistance in ten rapeseed-mustard genotypes against \u003cem\u003eL. erysimi\u003c/em\u003e. Significant genotypic variations were observed in aphid population, percentage of infested siliques, and aphid multiplication rate across crop stages. PM 25, PM 26, and DRMR 150\u0026thinsp;\u0026minus;\u0026thinsp;35 consistently recorded lower aphid infestations and were categorized as resistant, whereas IC 491023 and YST 151 were highly susceptible. Among the physical traits, surface wax content showed a strong negative correlation with aphid population, suggesting its critical role in resistance. PM 25 exhibited the highest wax content (7.30%), contributing to its superior resistance. The findings indicate that physical traits like surface wax act as a first line of defense by hindering aphid colonization and feeding. This study highlights the potential of integrating such traits into breeding programs, with PM 25 emerging as a promising genotype for developing aphid-resistant varieties.\u003c/p\u003e","manuscriptTitle":"Physical basis of host plant resistance in rapeseed and mustard against mustard aphid, Lipaphis erysimi (Kaltenbach)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-20 07:40:20","doi":"10.21203/rs.3.rs-7303385/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"98fb4d96-3981-4580-8278-88fc1e34884e","owner":[],"postedDate":"August 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-08T16:07:05+00:00","versionOfRecord":{"articleIdentity":"rs-7303385","link":"https://doi.org/10.1007/s11829-025-10209-2","journal":{"identity":"arthropod-plant-interactions","isVorOnly":false,"title":"Arthropod-Plant Interactions"},"publishedOn":"2025-12-05 15:58:16","publishedOnDateReadable":"December 5th, 2025"},"versionCreatedAt":"2025-08-20 07:40:20","video":"","vorDoi":"10.1007/s11829-025-10209-2","vorDoiUrl":"https://doi.org/10.1007/s11829-025-10209-2","workflowStages":[]},"version":"v1","identity":"rs-7303385","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7303385","identity":"rs-7303385","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}