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

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

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.