Self-incompatibility (SI) is a genetically based system in flowering plants that prevents self-fertilization and the adverse effects of inbreeding. However, SI is uncommon among weedy and invasive species in which small numbers of individuals often colonize new habitats. Common horsenettle, Solanum carolinense L., represents an exception to this pattern as it is a highly successful invasive that does exhibit SI. But the strength of SI in horsenettle exhibits significant variation within populations, making it a useful system for exploring the impacts of selfing on plant vigor, particularly the effects of selfing on plant defense mechanisms. The objectives of this research are to understand how variation in the strength of SI in horsenettle influences (1) induced plant responses, (2) host-plant quality, and (3) plant-herbivore-natural enemy interactions. The study will address these objectives using selfed and outcrossed progeny of plants derived from genets that differ in the strength of SI and employing a combination of greenhouse, field and laboratory studies.
This research will advance our understanding of plant-herbivore-natural enemy interactions and the mechanisms regulating plant responses to herbivory and also has important implications for managing weeds and further understanding their impacts on surrounding ecosystems.
