Species-level variation in bamboo allelopathy influences weed seedling establishment with implications for plant community dynamics

Bamboo stands contribute substantial quantities of leaf litter in many tropical and subtropical ecosystems, yet the potential role of bamboo-derived allelopathy in shaping plant community structure and seedling recruitment remains poorly understood. In this study, the allelopathic potential of leaves from nine bamboo species was assessed for their effects on early seedling performance of cultivated rice (MR297 and Putra) and eight distinct weedy rice biotypes. A preliminary lettuce (Lactuca sativa) bioassay confirmed phytotoxic activity and guided subsequent evaluations. The dish-pack assay was used to detect short-range volatile effects, while the sandwich (agar-embed) assay assessed the influence of water-soluble leachates at two concentrations. Multivariate analyses revealed significant species-level differences and strong bamboo × weedy rice interactions. Across assays, radicle elongation exhibited greater sensitivity than coleoptile growth, with responses varying according to bamboo species and dose. Bambusa multiplex and Dendrocalamus giganteus exhibited the most pronounced inhibitory effects, reducing radicle growth by more than 60% at higher leaf concentrations, whereas several other species showed weak or context-dependent effects. Differential responses among weedy rice biotypes indicated genetic variation in susceptibility. Although selective inhibition between cultivated and weedy rice was not evident, the results demonstrate that bamboo leaf inputs can substantially influence seedling establishment in a species-specific manner. These findings highlight the ecological role of bamboo litter allelopathy in mediating plant–plant interactions and offer insights into the mechanisms shaping community assembly in bamboo-dominated systems, with potential applications for sustainable management of weedy rice. Research Article Species-level variation in bamboo allelopathy influences weed seedling establishment with implications for plant community dynamics Siti Nurliyana Ghaffar 1, Nur Ardiyana Rejab 1,2, and Muhamad Shakirin Mispan 1,3 1 Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia 2 Centre for Research in Biotechnology for Agriculture (CEBAR), Universiti Malaya, 50603 Kuala Lumpur, Malaysia 3 Glami Lemi Biotechnology Research Centre, Universiti Malaya, 71450 Jelebu, Negeri Sembilan, Malaysia Author for correspondence: Muhamad Shakirin Mispan, Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia. (email: [email protected]; ORCID: 0000-0002-2413-1123) Bamboo stands contribute substantial quantities of leaf litter in many tropical and subtropical ecosystems, yet the potential role of bamboo-derived allelopathy in shaping plant community structure and seedling recruitment remains poorly understood. In this study, the allelopathic potential of leaves from nine bamboo species was assessed for their effects on early seedling performance of cultivated rice (MR297 and Putra) and eight distinct weedy rice biotypes. A preliminary lettuce ( Lactuca sativa ) bioassay confirmed phytotoxic activity and guided subsequent evaluations. The dish-pack assay was used to detect short-range volatile effects, while the sandwich (agar-embed) assay assessed the influence of water-soluble leachates at two concentrations. Multivariate analyses revealed significant species-level differences and strong bamboo × weedy rice interactions. Across assays, radicle elongation exhibited greater sensitivity than coleoptile growth, with responses varying according to bamboo species and dose. Bambusa multiplex and Dendrocalamus giganteus exhibited the most pronounced inhibitory effects, reducing radicle growth by more than 60% at higher leaf concentrations, whereas several other species showed weak or context-dependent effects. Differential responses among weedy rice biotypes indicated genetic variation in susceptibility. Although selective inhibition between cultivated and weedy rice was not evident, the results demonstrate that bamboo leaf inputs can substantially influence seedling establishment in a species-specific manner. These findings highlight the ecological role of bamboo litter allelopathy in mediating plant–plant interactions and offer insights into the mechanisms shaping community assembly in bamboo-dominated systems, with potential applications for sustainable management of weedy rice.

allelochemical interactions; bamboo litter; community assembly; phytotoxicity: weedy rice

Bamboo is a perennial grass that exhibits rapid growth, vigorous clonal expansion, and a strong capacity to colonize disturbed or open habitats. Many species spread through extensive rhizome networks, forming dense thickets that suppress understory vegetation and modify soil microenvironments. Such dominance contributes to bamboo’s ecological invasiveness and its ability to alter forest regeneration, nutrient cycling, and community composition (Rother et al., 2018; Yu et al., 2024). In tropical and subtropical regions, bamboo often becomes a structural and functional driver of ecosystem dynamics, particularly through high litter production and persistent belowground competition (Lima et al., 2012). Beyond its ecological influence, bamboo is an economically important non-timber resource valued for its use in construction, fiber, bioenergy, and food production. Ecologically, it plays a dual role by stabilizing soils and sequestering carbon while simultaneously reshaping plant communities through dense canopy formation and litter accumulation (Yu et al., 2024). The consistent suppression of neighboring vegetation has raised the possibility that bamboo exerts chemical interference or allelopathy through the release of secondary metabolites from leaves, litter, or roots. Phytochemical analyses of bamboo tissues have identified diverse phenolic acids, flavonoids, and benzoic derivatives with potential biological activity (Li et al., 2010; Kuang et al., 2017; Wang et al., 2024). These compounds may mediate chemical interactions that facilitate bamboo’s competitive success and limit the establishment of co-occurring species (An et al., 2024). Understanding such allelochemical interactions is essential for elucidating the mechanisms underlying bamboo dominance and its ecological effects on seedling recruitment and community assembly. Despite this potential, empirical studies comparing the allelopathic properties of multiple bamboo taxa under standardized conditions remain scarce. A systematic evaluation across species is therefore necessary to identify patterns of inhibitory activity and their implications for plant–plant chemical interactions. Interactions between bamboo and other grass species are of ecological interest because of their potential to affect recruitment dynamics in grass-dominated or agroecological landscapes. The genus Oryza, which includes both cultivated rice ( O. sativa ) and weedy conspecifics, provides an informative model system for exploring interspecific variation in allelopathic responses. Weedy rice is genetically diverse and ecologically resilient, often exhibiting rapid adaptation and strong competitive ability (Ziska et al., 2015; Avila et al., 2024). Differences in susceptibility among Oryza genotypes could reveal how allelochemicals influence population-level interactions and selective pressures within related species. This study aimed to (1) compare the allelopathic potential of leaves from nine tropical bamboo species using controlled bioassays, (2) evaluate their effects on early seedling growth of cultivated and weedy Oryza genotypes, and (3) examine interspecific and intraspecific variation in sensitivity to bamboo-derived chemical cues. This investigation provides a foundation for understanding how bamboo litter chemistry may influence seedling establishment, competitive hierarchies, and community assembly within grass-dominated systems.

Bamboo samples Fresh leaves from nine bamboo species, Bambusa multiplex (BM), Dendrocalamus giganteus (DG), Gigantochloa scortechinii (GS), Gigantochloa balui (GB), Schizostachyum brachycladum (SB), Gigantochloa ligulata (GL), Gigantochloa haskarliana (GH), Schizostachyum gracile (SG), and Vietnamosasa pusilla (VP) (Figure 1) were collected from Rimba Ilmu Botanical Garden, Universiti Malaya, Kuala Lumpur, Malaysia. The leaves were rinsed thoroughly under running water and air-dried for two weeks. To reduce potential contamination, the leaves were further oven-dried at 70 °C for three days. The dried samples were stored separately in zip-lock bags until further use in the experiments. Cultivated and weedy rice seed samples Seeds of two cultivated rice varieties, MR297 and Putra, were obtained from Loji Benih Padi, Kota Bharu, Kelantan (6°4’37.00513”N, 102°18’1.95424”E). Seeds of different weedy rice biotypes were collected from five rice field locations in Selangor, Malaysia, with sampling repeated at the same sites across two growing seasons (Table 1). All weedy rice biotypes displayed straw-colored hulls, red pericarps, and a high degree of seed shattering. The seeds were cleaned, separated from debris, and air-dried in a greenhouse at 34 °C/25 °C (day/night) for three days. They were then stored in sealed plastic bags with silica gel desiccants in a dry cabinet at room temperature for approximately 100 days to break seed dormancy. Allelopathic screening of bamboo plants The allelopathic potential of bamboo leaves was evaluated using the dish-pack and sandwich bioassay methods (Fujii, 2001). Lettuce ( Lactuca sativa ) seeds were initially used as a model test species due to their reliability in germination and sensitivity to both inhibitory and stimulatory chemicals (Fujii et al., 2003). Seeds were purchased from Green World Genetics Sdn. Bhd. Volatile allelopathic activity was assessed using a dish-pack setup modified from Fujii et al. (2005). Dried bamboo leaves (200 mg) were placed in the central well of a six-well plate. The surrounding wells were lined with filter paper moistened with 0.75 mL of distilled water and sown with seven lettuce seeds each. Wells without plant material served as controls. The plates were sealed with cellophane tape, wrapped in aluminum foil to block light, and incubated at 30 °C for three days. After incubation, radicle and hypocotyl lengths were measured to assess growth relative to distance from the central well. Allelopathic effects mediated by aqueous leachates were examined using the sandwich method (Fujii, 2001). Each well of a six-well plate was filled with 5 mL of autoclaved agar and allowed to solidify under sterile conditions. Dried leaf material (10 mg or 50 mg) was placed on the agar surface and covered with an additional 5 mL of agar to embed the sample between two layers, allowing gradual release of leachates during the bioassay. Five lettuce seeds were placed on top of the second agar layer. The plates were sealed with parafilm and incubated in complete darkness at 30 °C. Control wells contained only agar without leaf material. Seedling growth was measured on day seven by recording radicle and hypocotyl lengths and weights. Each treatment was conducted in three replicates. Allelopathic bioassay on cultivated and weedy rice The dish-pack and sandwich methods were similarly applied to cultivated and weedy rice seedlings, substituting rice seeds for lettuce. Prior to the bioassays, seeds were surface sterilized to eliminate contaminants that could affect germination or growth. Seeds were soaked in a commercial 10% sodium hypochlorite solution and gently swirled for two minutes to remove air bubbles and ensure complete exposure. They were then rinsed thoroughly with distilled water and placed on Whatman No. 1 filter paper to air dry before use. After treatment, rice seedlings were removed from the media, gently separated from any remaining agar or filter paper, and rinsed with distilled water. Excess water was removed by lightly blotting with tissue paper. Seedling growth was assessed by measuring the lengths of radicles and coleoptiles from base to tip. The percentage of growth inhibition was calculated using the formula: \begin{equation} \text{Inhibition}\text{\ (\%)\ =\ 100\ -\ }\left(\frac{\text{a}}{\text{b}}\right)\text{×100\%}\nonumber \\ \end{equation} Where: a = Average growth measurement of the treatment (experimental group) b = Average growth measurement of the control group Positive values indicate an inhibitory effect, while negative values indicate a promotive effect relative to the control. Statistical analysis Data for each experiment (lettuce screening, cultivated rice, weedy rice) were subjected to analysis of variance (ANOVA) in a completely randomized design. For the weedy rice sandwich assay, a three-way ANOVA was performed with bamboo species, concentration, and weedy rice biotype as fixed factors. The analysis was conducted separately for coleoptile and radicle length. Where significant interactions were found (P < 0.05), simple effects were examined. A multivariate analysis of variance (MANOVA) was also performed on the combined coleoptile and radicle length data for the weedy rice experiment to assess the overall treatment effect. Post hoc comparisons for significant main effects were performed using Tukey’s Honest Significant Difference (HSD) test at α = 0.05. All analyses were conducted using SAS OnDemand for Academics (SAS Institute Inc., Cary, NC, USA).

Preliminary test with lettuce seeds The preliminary screening of bamboo species using lettuce seeds in both the dish-pack and sandwich assays revealed statistically significant differences among treatments (P < 0.001) for all measured parameters (Figure 2; Table S1). These results demonstrate that the leaf material from the tested bamboo species can markedly affect the growth of lettuce seedlings. The findings provide empirical evidence that potential allelochemical compounds in bamboo leaves influence seedling development and support the rationale for extending the bioassays to cultivated and weedy rice seeds. Effect on the Seedling Growth of Cultivated Rice Responses of the two cultivated varieties, MR297 and Putra, differed markedly by assay type, bamboo species and dose (Figure 3, Table S2). MR297 coleoptile responses to bamboo volatiles in dish-pack assay were variable and often negatively inhibitive (Figure 3a). At 41 mm distance, several species induced apparent negative inhibition on coleoptile elongation (e.g. G. scortechinii, −46.11%; D. giganteus, −40.00%; and B. multiplex, −41.11%). MR297 radicle responses also varied with distance and species, showing both strong inhibition and negative inhibition (i.e., promotion) at different distances (Figure 3b). By contrast, Putra was generally more susceptible to volatile-mediated inhibition (Figure 3c-d). Putra coleoptile inhibition was positive for most species and distances such as D. giganteus (29.94%) at 41 mm, while Putra radicle inhibition switch to promotion when moved away from the source well for six bamboo species (i.e. BM, GB, GH, GL, GS, and VP). In sandwich assays the effect of embedded leaf mass was pronounced, particularly for radicle length (Figure 4). For MR297 coleoptiles responses were mixed at 10 mg and 50 mg, with some species producing modest inhibition (DG, GB, GH, GL, GS) and others exhibiting negative inhibition (Figure 4a). MR297 radicle inhibition increased markedly with dose in several species. For example, B. multiplex (BM) increased from 12.18% inhibition at 10 mg to 61.47% at 50 mg, and G. balui (GB) shifted from −1.41% to 57.99% (Figure 4b). Putra showed more consistent inhibition in the sandwich assay for both coleoptile and radicle measurements as compared with MR297. Majority bamboo specie showed inhibition effect especially at 50mg concentration except for Schizostachyum gracile (SG) towards radicle length (Figure 4d). Radicle inhibition at 50 mg frequently exceeded 40–60% for several species (Figure 4b-d). Allelopathic Effect on the Seedling Growth of Weedy Rice Bamboo leaves used in this study showed highly significant effects on the coleoptile and radicle lengths of weedy rice biotypes (Figure 5, Table S3). Significant bamboo × weedy rice biotype interactions were observed for both traits indicating that the magnitude and direction of allelopathic effects depended on the identity of the biotype tested (Tables 2 and 3). MANOVA confirmed a significant overall effect of bamboo species, concentration, and weedy rice biotype on the combined coleoptile and radicle growth (P < 0.001; Table 4). Tukey HSD groupings showed clear species-level contrasts (Figure 5). The control (no leaf material) consistently had the largest mean coleoptile and radicle values and differed significantly from most bamboo treatments (Figure 5a-c). Among bamboo species, Bambusa multiplex and Dendrocalamus giganteus had consistently resulted in the strongest inhibition, particularly for radicle growth. Conversely, species such as Schizostachyum brachycladum and Schizostachyum gracile generally produced weaker and more variable inhibition. Radicle measures provided finer discrimination among bamboo species than coleoptile measures, consistent with the significant bamboo × concentration interaction in the radicle (Table 4). This indicates that certain bamboo species exert stronger inhibitory effects on Oryza spp. seedlings. For weedy rice responses (Figure 5b-d), clear grouping patterns were observed. Weedy rice biotype WR31.S2 and WR35.S2 recorded the longest coleoptile length significantly higher than WR33.S1 and WR32.S11 (Figure 5b). Similar pattern also observed for the radical length where weedy rice biotypes WR32.S1, WR33.S1, WR35.S2, and WR33.S2 were more susceptible than the remaining biotypes (Figure 5d). This described the degree of tolerance/susceptible of different weedy rice biotypes towards allelopathic leachate of bamboo leaves.

Ecological implications of bamboo allelopathy The consistent inhibition of lettuce (Figure 2), cultivated rice (Figures 3,4), and weedy rice (Figure 5) seedlings demonstrates that allelopathic activity is widespread but species-specific within bamboo. This study provides one of the first systematic, cross-species comparisons of bamboo allelopathy, showing that phytochemical interference is a common ecological strategy contributing to bamboo dominance (Ogita & Sasamoto, 2017; Yu et al., 2024). Variation among the nine bamboo taxa indicates that allelopathic potential is linked to distinct phytochemical profiles, with Bambusa multiplex and Dendrocalamus giganteus producing the strongest inhibition, consistent with reported differences in phenolic acids, flavonoids, and benzoic derivatives (Kuang et al., 2017; Wang et al., 2024). Such chemical heterogeneity likely drives differences in understory suppression and regeneration patterns (Lima et al., 2012; Luo et al., 2024). Seedling radicles were more sensitive than coleoptiles, reflecting roots as the primary interface for allelochemical uptake (Belz, 2007). Stronger inhibition in sandwich versus dish-pack assays suggests water-soluble compounds mediate phytotoxicity via litter leachates and decomposition runoff (Fujii et al., 2005; Wang et al., 2024). Dose-dependent effects, including occasional low-concentration stimulation, indicate that small litter inputs may transiently enhance establishment, whereas dense litter suppresses recruitment and creates “bare zones” (Belz, 2007). Genotype-dependent responses in cultivated and weedy rice highlight that allelopathic effects are not uniform. Stronger inhibition of certain weedy rice biotypes suggests trade-offs between competitive traits and chemical susceptibility, reflecting potential selective pressures shaping population structure and community composition (Jabran et al., 2015; Ziska et al., 2015). Water-soluble allelochemicals, together with shading, likely explain reduced understory diversity and seedling establishment under dense bamboo canopies, reinforcing bamboo dominance and influencing successional trajectories (Yu et al., 2024). Controlled experiments here provide a mechanistic framework for field studies on litter chemistry, soil interactions, and microbial mediation, with B. multiplex and D. giganteus prioritized for follow-up research. Potential applications for sustainable management of weedy rice Beyond ecological insights, these findings suggest that species-specific bamboo allelopathy could be leveraged to manage weedy rice in rice agroecosystems. The strong, water-soluble inhibitory effects observed in certain bamboo species highlight a potential eco-friendly approach to suppress problematic weedy rice biotypes consequently reducing reliance on synthetic herbicides. Controlled incorporation of bamboo litter or extracts may selectively inhibit sensitive weedy rice genotypes while minimally affecting crop plants, providing a pathway for sustainable weed management integrated with ecological principles. This highlights the dual value of bamboo allelopathy in both ecological theory and sustainable agroecosystem management.

Bamboo exhibits widespread, species-specific allelopathic activity, with Bambusa multiplex and Dendrocalamus giganteus strongly inhibiting seedling growth, particularly at roots and via water-soluble compounds. Dose-dependent and genotype-specific responses highlight how chemical interactions shape intraspecific variation, community composition, and understory dynamics. By combining shading and phytochemical interference, bamboo reinforces its dominance and influences successional trajectories. These findings provide a mechanistic framework for understanding plant–plant chemical interactions, litter-mediated ecological feedbacks, and the role of allelopathy in structuring tropical and subtropical plant communities, while also revealing potential avenues for sustainable, eco-friendly management of weedy rice through targeted use of bamboo litter.

The authors would like to express their sincere gratitude to Mr. Mohd Shahmi Hakimi Mazlishah from Glami Lemi Biotechnology Research Center for his invaluable technical support throughout the research. This research was funded by Fundamental Research Grant Scheme, Ministry of Higher Education Malaysia, grant number FRGS/1/2019/WAB01/UM/02/4 . Declarations Conflict of interest The authors have no relevant financial or non-financial interests to disclose. The authors have no competing interests to declare that are relevant to the content of this article. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. The authors have no financial or proprietary interests in any material discussed in this article. Authors’ contribution All authors contributed to the study conception and design. Experimental design was developed by Muhamad Shakirin Mispan and Nur Ardiyana Rejab. Material preparation, data collection and analysis were performed by Siti Nurliyana Ghaffar. The first draft of the manuscript was written by Siti Nurliyana Ghaffar, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

An, M., Zhu, M., & Zhao, G. (2024). Allelochemicals from Moso bamboo: Identification and their effects on neighbor species. Forests, 15(11), 2040. https://doi.org/10.3390/f15112040 Avila, L. A., Ziska, L. H., Norsworthy, J. K., & Burgos, N. R. (2024). From the Clearfield® to the Provisia™ system for rice production: Challenges and management opportunities. Advances in Weed Science, 42, e020242042. https://doi.org/10.51694/AdvWeedSci/2024;42:00028 Belz, R. G. (2007). Allelopathy in crop/weed interactions—an update. Pest Management Science, *63*(4), 308–326. https://doi.org/10.1002/ps.1320 Farooq, M., Jabran, K., Cheema, Z. A., Wahid, A., & Siddique, K. H. (2011). The role of allelopathy in agricultural pest management. Pest Management Science, *67*(5), 493–506. https://doi.org/10.1002/ps.2091 Fujii, Y., Matsuyama, M., Hiradate, S., & Shimozawa, H. (2005). Dish pack method: A new bioassay for volatile allelopathy. In J. D. I. Harper, M. An, H. Wu, & J. H. Kent (Eds.), Proceedings of the 4th World Congress on Allelopathy (pp. 493–497). Fujii, Y., Parvez, S. S., Parvez, M. M., Ohmae, Y., & Iida, O. (2003). Screening of 239 medicinal plant species for allelopathic activity using the sandwich method. Weed Biology and Management, 3 (4), 233–241. http://dx.doi.org/10.1046/j.1444-6162.2003.00111.x Fujii, Y., Shibuya, T., Nakatani, K., Itani, T., Hiradate, S., & Parvez, M. M. (2004). Assessment method for allelopathic effect from leaf litter leachates. Weed Biology and Management, 4 (1), 19–23. https://doi.org/10.1111/j.1445-6664.2003.00113.x Jabran, K., Mahajan, G., Sardana, V., & Chauhan, B. S. (2015). Allelopathy for weed control in agricultural systems. Crop Protection, *72*, 57–65. https://doi.org/10.1016/j.cropro.2015.03.004 Kuang, Y., Yang, S. X., Sampietro, D. A., Zhang, X. F., Tan, J., Gao, Q. X., Liu, H. W., Ni, Q. X., & Zhang, Y. Z. (2017). Phytotoxicity of leaf constituents from bamboo ( Shibataea chinensis Nakai) on germination and seedling growth of lettuce and cucumber. Allelopathy Journal, 40(2), 133–142. https://doi.org/10.26651/2017-40-2-1072 Li, Z.-H., Wang, Q., Ruan, X., Pan, C.-D., & Jiang, D.-A. (2010). Phenolics and plant allelopathy. Molecules, 15(12), 8933–8952. https://doi.org/10.3390/molecules15128933 Lima, R. A. F., Rother, D. C., Muler, A. E., Lepsch, I. F., & Rodrigues, R. R. (2012). Bamboo overabundance alters forest structure and dynamics in the Atlantic Forest hotspot. Biological Conservation, 147(1), 32–39. https://doi.org/10.1016/j.biocon.2012.01.015 Luo, W., Sun, Y., Wang, Y., He, Y., Zhang, W., & Zhang, J. (2024). Understory bamboo removal impacts on woody seedling regeneration in forest ecosystems: a meta-analysis. Ecological Processes, *13*(1), 35. https://doi.org/10.1186/s13717-024-00526-4 Ogita, S., & Sasamoto, H. (2017). In vitro bioassay of allelopathy in four bamboo species ( Bambusa multiplex, Phyllostachys bambusoides, P. nigra, Sasa kurilensis ) using sandwich and protoplast co-culture methods. American Journal of Plant Sciences, *8*(7), 1699–1710. https://doi.org/10.4236/ajps.2017.87117 Rother, D. C., Gorgens, E., Guerin, N., Rodrigues, R. R., & Pizo, M. A. (2018). Seedling community in a patchy tropical vegetation under the influence of bamboos. Tropical Conservation Science, 11, 1–12. https://doi.org/10.1177/1940082918767124 Wang, A., Huang, K., Ning, Y., & Bi, Y. (2024). Allelochemicals from Moso bamboo: Identification and their effects on neighbor species. Forests, 15(11), 2040. https://doi.org/10.3390/f15112040 Yu, J., Le, C., Peñuelas, J., Sardans, J., Xu, X., Zou, C., Zhang, Y., Li, T., Mao, X., Cheng, W., & Zhong, Z. (2024). Trait divergence and opposite above- and below-ground strategies facilitate Moso bamboo invasion into subtropical evergreen broadleaf forest. Plant Science, 393, 112715. https://doi.org/10.1016/j.plantsci.2024.112715 Ziska, L. H., Gealy, D. R., Burgos, N., Caicedo, A. L., Gressel, J., Lawton-Rauh, A. L., Avila, L. A., Theisen, G., Norsworthy, J., Ferrero, A., Vidotto, F., Johnson, D. E., Ferreira, F. G., Marchesan, E., Menezes, V., Cowie, A., & Yamasue, Y. (2015). Weedy (Red) Rice: An Emerging Constraint to Global Rice Production. Advances in Agronomy, *129*, 181–228. https://doi.org/10.1016/bs.agron.2014.09.003 Table 1. Summary of weedy and cultivated rice used in this study | Weedy rice | ||||| | WR30.S1 | 3°42’51.0”N 100°59’57.0”E | 2022 | Red | Awnless | Shattered | | WR31.S2 | 3°42’51.0”N 100°59’57.0”E | 2023 | Red | Awnless | Shattered | | WR32.S1 | 3°40’59.5”N 100°59’22.0”E | 2022 | Red | Awned | Shattered | | WR32.S2 | 3°40’59.5”N 100°59’22.0”E | 2023 | Red | Awned | Shattered | | WR33.S1 | 3°41’01.2”N 100°59’20.3”E | 2022 | Red | Awnless | Shattered | | WR33.S2 | 3°41’01.2”N 100°59’20.3”E | 2023 | Red | Awnless | Shattered | | WR34.S2 | 3°42’10.2”N 100°59’27.3”E | 2023 | Red | Awned | Shattered | | WR35.S2 | 3°42’30.2”N 100°58’49.3”E | 2023 | Red | Awnless | Shattered | | Cultivated Rice | ||||| | MR297 | - | - | White | Awnless | Non-shattered | | PUTRA | - | - | White | Awnless | Non-shattered | Table 2. Analysis of variance (ANOVA) for coleoptile length of weedy rice seedlings exposed to bamboo leaf extracts using the sandwich method. | Bamboo species | 9 | 446.87 | 5.03 | <0.0001 | | Concentration | 1 | 1765.89 | 19.9 | <0.0001 | | Bamboo × Concentration | 9 | 141.16 | 1.59 | 0.1169 | | Weedy rice (WR) biotype | 7 | 3457.17 | 38.95 | <0.0001 | | Bamboo × WR Biotype | 63 | 244.14 | 2.75 | <0.0001 | | Concentration × WR Biotype | 7 | 93.42 | 1.05 | 0.3942 | | Bamboo × Concentration × WR Biotype | 63 | 102.04 | 1.15 | 0.2209 | | Error | 320 | 88.76 | Table 3. Analysis of variance (ANOVA) for radicle length of weedy rice seedlings exposed to bamboo leaf extracts using the sandwich method. | Bamboo species | 9 | 1966.73 | 16 | <0.0001 | | Concentration | 1 | 5831.1 | 47.44 | <0.0001 | | Bamboo × Concentration | 9 | 444.81 | 3.62 | 0.0003 | | Weedy rice (WR) biotype | 7 | 1128.25 | 9.18 | <0.0001 | | Bamboo × WR Biotype | 63 | 277.94 | 2.26 | <0.0001 | | Concentration × WR Biotype | 7 | 146.59 | 1.19 | 0.3064 | | Bamboo × Concentration × WR Biotype | 63 | 116.33 | 0.95 | 0.5933 | | Error | 320 | 122.91 | Table 4. Multivariate analysis of variance (MANOVA) for the effects of bamboo species, concentration, and weedy rice biotype on coleoptile and radicle length of weedy rice seedlings. | Bamboo species | Wilks’ Lambda | 0.663 | 8.09 | 18 | 638 | <0.0001 | | Pillai’s Trace | 0.349 | 7.51 | 18 | 640 | <0.0001 | | | Hotelling Trace | 0.491 | 8.67 | 18 | 528 | <0.0001 | | | Roy’s Root | 0.451 | 16.03 | 9 | 320 | <0.0001 | | | Concentration | Wilks’ Lambda | 0.866 | 24.69 | 2 | 319 | <0.0001 | | Pillai’s Trace | 0.134 | 24.69 | 2 | 319 | <0.0001 | | | Hotelling Trace | 0.155 | 24.69 | 2 | 319 | <0.0001 | | | Roy’s Root | 0.155 | 24.69 | 2 | 319 | <0.0001 | | | Weedy rice biotype | Wilks’ Lambda | 0.407 | 25.89 | 14 | 638 | <0.0001 | | Pillai’s Trace | 0.679 | 23.49 | 14 | 640 | <0.0001 | | | Hotelling Trace | 1.249 | 28.39 | 14 | 507 | <0.0001 | | | Roy’s Root | 1.049 | 47.94 | 7 | 320 | <0.0001 | Figure 1. Images of bamboo plants used in this study. a. Bambusa multiplex (BM) ; b. Dendrocalamus giganteus (DG); c. Gigantochloa scortechinii (GS); d. Gigantochloa balui (GB); e. Schizostachyum brachycladum (SB); f. Gigantochloa ligulate (GL); g. Gigantochloa haskarliana (GH); h. Schizostachyum gracile (SG); i. Vietnamosasa pusilla (VP). Figure 2. Effect of bamboo leaves on the hypocotyl and radicle lengths of lettuce seeds using sandwich (a-b) and dish-pack (c-d) methods. Error bars indicate standard error of the mean. Figure 3. Effect of leaf volatilization from various bamboo species on rice seedling growth using the dishpack method. Inhibition percentage of coleoptile elongation and radicle elongation of rice varieties MR297 (a-b) and Putra (c-d). Refer to Figure 1 for bamboo species abbreviation. Figure 4. Effect of leaf leachate from various bamboo species on rice seedling growth using the sandwich method. Inhibition percentage of coleoptile elongation and radicle elongation of rice varieties MR297 (a-b) and Putra (c-d). Refer to Figure 1 for bamboo species abbreviation. Figure 5. Effect of leaf leachate from various bamboo species on weedy rice seedling growth using the sandwich method. (a) and (c) are the effect of various bamboo species against weedy rice seedling on the coleoptile and radicle lengths, respectively. (b) and (d) are the different responses of various weedy rice biotypes towards bamboo species on the coleoptile and radicle lengths, respectively. Bars annotated with different letters differ significantly at P < 0.05. List of supplementary data Table S1. Table S1. Hypocotyl and radicle length of lettuce in dishpack and sandwich methods. Bambusa multiplex (BM), Dendrocalamus giganteus (DG), Gigantochloa scortechinii (GS), Gigantochloa balui (GB), Schizostachyum brachycladum (SB), Gigantochloa ligulata (GL), Gigantochloa haskarliana (GH), Schizostachyum gracile (SG), and Vietnamosasa pusilla (VP). Table S2. Coleoptile and radicle length of cultivated rice (MR297 and Putra) in dishpack and sandwich methods. Bambusa multiplex (BM), Dendrocalamus giganteus (DG), Gigantochloa scortechinii (GS), Gigantochloa balui (GB), Schizostachyum brachycladum (SB), Gigantochloa ligulata (GL), Gigantochloa haskarliana (GH), Schizostachyum gracile (SG), and Vietnamosasa pusilla (VP). Table S3 . Coleoptile and radicle length of weedy rice in sandwich method. Bambusa multiplex (BM), Dendrocalamus giganteus (DG), Gigantochloa scortechinii (GS), Gigantochloa balui (GB), Schizostachyum brachycladum (SB), Gigantochloa ligulata (GL), Gigantochloa haskarliana (GH), Schizostachyum gracile (SG), and Vietnamosasa pusilla (VP). Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 419views 217downloads Citations Download citation Siti Nurliyana Ghaffar, Nur Ardiyana Rejab, Muhamad Shakirin Mispan. Species-level variation in bamboo allelopathy influences weed seedling establishment with implications for plant community dynamics. Authorea. 18 November 2025. DOI: https://doi.org/10.22541/au.176344038.85088068/v1 DOI: https://doi.org/10.22541/au.176344038.85088068/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.