Abstract:
Species interactions and mechanisms affect plant coexistence and community assembly. Despite increasing knowledge of kin recognition and allelopathy in regulating inter-specific and intra-specific interactions among plants, little is known about whether kin recognition mediates allelopathic interference. We used allelopathic rice cultivars with the ability for kin recognition grown in kin versus non-kin mixtures to determine their impacts on paddy weeds in field trials and a series of controlled experiments. We experimentally tested potential mechanisms of the interaction via altered root behaviour, allelochemical production and resource partitioning in the dominant weed competitor, as well as soil microbial communities. We consistently found that the establishment and growth of paddy weeds were more inhibited by kin mixtures compared to non-kin mixtures. The effect was driven by kin recognition that induced changes in root placement, altered weed carbon and nitrogen partitioning, but was associated with similar soil microbial communities. Importantly, genetic relatedness enhanced the production of intrusive roots towards weeds and reduced the production of rice allelochemicals. These findings suggest that relatedness allows allelopathic plants to discriminate their neighbouring collaborators (kin) or competitors and adjust their growth, competitiveness and chemical defense accordingly.
摘要:
物种相互作用和机制影响植物共存和群落组装。尽管在调节植物之间的种间和种内相互作用方面越来越了解亲属识别和化感作用,关于亲属识别是否介导化感干扰知之甚少。我们使用具有亲缘和非亲缘混合物中生长的亲缘识别能力的化感水稻品种,以在田间试验和一系列对照实验中确定其对稻田杂草的影响。我们通过改变根系行为实验测试了相互作用的潜在机制,优势杂草竞争对手的化感生产和资源分配,以及土壤微生物群落。我们一致发现,与非亲属混合物相比,亲属混合物对稻田杂草的建立和生长的抑制作用更大。这种效应是由亲属识别驱动的,这种识别引起了根位置的变化,改变了杂草的碳和氮分配,但与相似的土壤微生物群落有关。重要的是,遗传相关性增强了对杂草的侵入根的产生,并减少了水稻化感物质的产生。这些发现表明,亲缘关系允许化感植物区分其邻近的合作者(亲属)或竞争对手并调整其生长,相应的竞争力和化学防御。