DISSERTATION RESEARCH: Carnivorous plant syndromes: The role of volatile emissions in the diversification of the pitcher plant genus Sarracenia

确定在一个谱系内驱动多样性的机制是进化生物学家的一个关键兴趣。对于植物来说，与昆虫的相互作用被认为是生物多样性的重要驱动因素，最明显的是通过草食和授粉。食肉植物的独特之处在于，虽然它们在很大程度上依赖昆虫作为传粉者，但它们也以昆虫为重要的营养资源。这项研究以北美猪笼草属植物Sarracenia为模型，研究植物与昆虫的相互作用如何促进食肉植物的进化。具体地说，它研究了这些相互作用如何促成了食肉植物用来吸引和捕获昆虫作为猎物的化学信号，同时避免捕获它们的昆虫传粉者。一名本科生将接受实地和实验室技术方面的指导。这项研究的结果将被纳入K-12教育计划和本科课程，并将广泛传播给公众。先前的研究表明，存在与猎物专门化或猎物分割相关的“食肉综合征”，或紧密相关的诱捕特征(例如毛状体密度、高度)。这项研究将研究诱人的诱捕特征，特别是挥发性排放，是否与捕食者在不同物种之间的分割有额外的关联。通过使用研究人员最近生成的系统发育图作为框架，并以亚特兰大植物园维护的一个室外公共花园为框架，该项目检查了减少捕获传粉者的机制是否进一步导致了猎物的专业化。在捕捉器的30天寿命内，将从14个假定的Sarracenia分类群中收集挥发物排放。挥发分剖面和以前测量的圈闭特征之间的统计相关性将使用系统发育广义最小二乘分析进行检验。所产生的挥发性排放将与捕获的猎物进行比较，还将使用系统发育广义最小二乘分析。花的挥发物将被检测，并与瓶子的挥发物进行比较，以测试化学线索的变化。此外，还将测量和统计分析花朵和陷阱之间的时间和空间分离，以检验总体假设。

Identifying the mechanisms that drive diversification within a lineage is a key interest of evolutionary biologists. For plants, interactions with insects are thought to be important drivers of biodiversity, most obviously through herbivory and pollination. Carnivorous plants are unique in that, while they largely rely on insects as pollinators, they also prey upon them as a vital nutrient resource. This research studies how plant-insect interactions have contributed to carnivorous plant evolution using the North American Pitcher Plant genus, Sarracenia, as a model. Specifically, it studies how these interactions have contributed to the chemical signaling that carnivorous plants use to attract and capture insects as prey, while simultaneously avoiding capturing their insect pollinators. One undergraduate will be mentored in field and laboratory techniques. Results from this research will be incorporated into K-12 education programs and undergraduate classes, and will be broadly disseminated to the public. Previous research suggests that there are 'carnivorous syndromes', or tightly correlated trapping traits (e.g., trichome density, height) that are associated with prey specialization or prey partitioning. This research will examine whether 'attractive' trap traits, specifically volatile emissions, are additionally correlated with prey partitioning across Sarracenia species. By using a recent phylogeny generated by the researchers as a framework and an outdoor common garden maintained by the Atlanta Botanical Garden, this project examines whether mechanisms to alleviate capturing pollinators have further resulted in prey specialization. Volatiles emissions will be collected from 14 putative Sarracenia taxa over the 30-day lifespan of the traps. Statistical correlations among volatile profiles and previously measured trap traits will be examined using a phylogenetic generalized least square analysis. The resulting volatile emissions will be compared to prey captured also using a phylogenetic generalized least square analysis. Flower volatiles will be examined and compared to pitcher volatiles to test for variation in chemical cues. Temporal and spatial separation between flowers and traps will additionally be measured and analyzed statistically to test the overarching hypotheses.