Data from: Multiple plant traits shape the genetic basis of herbivore community assembly

1. Community genetics research has posited a genetic basis to the assembly of ecological communities. For arthropod herbivores in particular, there is strong support that genetic variation in host plants is a key factor shaping their diversity and composition. However, the specific plant phenotypes underlying herbivore responses remain poorly explored for most systems. 2. We address this knowledge gap by examining the influence of both genetic and phenotypic variation in a dominant host-plant species, Salix hookeriana, on its associated arthropod herbivore community in a common garden experiment. Specifically, we surveyed herbivore responses among five different arthropod feeding guilds to 26 distinct S. hookeriana genotypes. Moreover, we quantified the heritability of a suite of plant traits that determine leaf quality (e.g. phenolic compounds, trichomes, specific leaf area, C : N) and whole-plant architecture, to identify which traits best accounted for herbivore community responses to S. hookeriana genotype. 3. We found that total herbivore abundance and community composition differed considerably among S. hookeriana genotypes, with strong and independent responses of several species and feeding guilds driving these patterns. We also found that leaf phenolic chemistry displayed extensive heritable variation, whereas leaf physiology and plant architecture tended to be less heritable. Of these traits, herbivore responses were primarily associated with leaf phenolics and plant architecture; however, different herbivore species and feeding guilds were associated with different sets of traits. Despite our thorough trait survey, plant genotype remained a significant predictor of herbivore responses in most trait association analyses, suggesting that unmeasured host-plant characteristics and/or interspecific interactions were also contributing factors. 4. Taken together, our results support that the genetic basis of herbivore community assembly occurs through a suite of plant traits for different herbivore species and feeding guilds. Still, identifying these phenotypic mechanisms requires measuring a broad range of plant traits and likely further consideration of how these traits affect interspecific interactions.

1. 群落遗传学（community genetics）研究提出，生态群落的组装存在遗传基础。尤其对于节肢草食动物（arthropod herbivores）而言，已有充分证据支持宿主植物的遗传变异是塑造其多样性与组成的关键因素。然而，在多数研究系统中，介导草食动物响应的具体植物表型仍未得到充分探索。2. 本研究通过同质园实验（common garden experiment），探究优势宿主植物Hooker柳（Salix hookeriana）的遗传与表型变异对其伴生节肢草食动物群落的影响，以填补这一研究空白。具体而言，我们针对26个不同的Hooker柳基因型，调查了5类不同节肢动物取食功能群（feeding guilds）的草食动物响应情况。此外，我们量化了一系列决定叶片品质的植物性状（如酚类化合物、毛状体（trichomes）、比叶面积（specific leaf area）、碳氮比（C:N））以及全株构型的遗传力（heritability），以明确哪些性状最能解释草食动物群落对Hooker柳基因型的响应。3. 研究结果显示，不同Hooker柳基因型的总草食动物丰度与群落组成存在显著差异，多个物种及取食功能群的独立强响应驱动了这一格局。我们还发现，叶片酚类化学组成具有广泛的可遗传变异，而叶片生理性状与植株构型的遗传力相对较低。在这些性状中，草食动物的响应主要与叶片酚类物质及植株构型相关；不过，不同草食动物物种及取食功能群对应的性状组合各不相同。尽管我们开展了全面的性状调查，在多数性状关联分析中，植物基因型仍对草食动物响应具有显著预测能力，这表明未被测量的宿主植物特征和/或种间相互作用（interspecific interactions）也是重要的影响因素。4. 综上，本研究结果支持：草食动物群落组装的遗传基础通过针对不同草食动物物种与取食功能群的一系列植物性状实现。不过，要阐明这些表型机制，需要测定更广泛的植物性状，且可能需要进一步考量这些性状如何影响种间相互作用。