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

确定驱动谱系内多样化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力，最明显的是通过食草和授粉。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，但它们也捕食昆虫作为重要的营养来源。本研究以北美猪笼草属（Sarracenia）为模型，研究植物与昆虫的相互作用如何促进了食肉植物的进化。具体来说，它研究了这些相互作用如何促成食肉植物用来吸引和捕获昆虫作为猎物的化学信号，同时避免捕获昆虫传粉者。一名本科生将在现场和实验室技术指导。该研究结果将被纳入K-12教育课程和本科课程，并将广泛传播给公众。先前的研究表明，存在“食肉综合征”，或与猎物专门化或猎物分配相关的紧密相关的捕获特征（例如，毛密度、高度）。这项研究将检验“吸引人的”陷阱特征，特别是挥发性排放物，是否与Sarracenia物种之间的猎物分配有关。通过使用研究人员最近生成的系统发育作为框架和亚特兰大植物园维护的室外公共花园，该项目研究了减轻捕捉传粉媒介的机制是否进一步导致了猎物专业化。在捕集器30天的使用寿命内，将收集14个假定的Sarracenia分类群的挥发物排放。挥发性剖面和先前测量的陷阱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查。由此产生的挥发性排放将与捕获的猎物进行比较，也使用系统发育广义最小二乘分析。花挥发物将被检查，并与投手挥发物进行比较，以测试化学线索的变化。此外，花和陷阱之间的时空分离将被测量和统计分析，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.