Dissertation Research: Effects of Self Incompatibility on Inbreeding Depression with Respect to Plant Defenses

自交不亲和（SI）是开花植物中一种基于遗传的系统，它阻止了自交受精和近交的不利影响。然而，SI在杂草和入侵物种中并不常见，在这些物种中，很少有个体在新的栖息地定居。常见的马蹄铁，Solanum carolinense L.，代表了这种模式的一个例外，因为它是一种非常成功的侵入性，确实表现出SI。但是，刺麻的自交强度在种群内表现出显著的差异，使其成为探索自交对植物活力影响，特别是自交对植物防御机制影响的有用系统。本研究的目的是了解马蹄草中SI强度的变化如何影响(1)诱导的植物反应，(2)寄主-植物质量，以及(3)植物-食草动物-天敌相互作用。该研究将利用来自SI强度不同基因的植物的自交和异交后代，并采用温室、田间和实验室研究相结合的方法来实现这些目标。本研究将促进我们对植物-草食动物-天敌相互作用和植物对草食反应的调节机制的认识，并对杂草管理和进一步了解其对周围生态系统的影响具有重要意义。

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.