DISSERTATION RESEARCH: The Effect of Vegetative Herbivory on the Mating System and on the Demographic Value of Selfed and Outcrossed Progeny

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

A central question of population biology is to understand the causes and consequences of mating system variation. Biologists have recognized the importance of both environmental and genetic factors in the evolution of plant mating systems. However, very few studies have examined the role of antagonists (e.g., herbivores/pathogens). Herbivores are one of the most important factors limiting plant reproduction, and are likely to affect mating system evolution. The proposed work tests hypotheses on the mechanisms of herbivore-mediated mating system variation in a native plant, Impatiens capensis. The investigators will further extend this work to understand how changes in the mating system as a result of herbivory affect the population dynamics of I. capensis. A combination of field experiments that manipulate herbivore levels, molecular genetic analyses, and demographic analyses will be used to address these goals. The results of these experiments will offer important insight to the ecological causes and long-term consequences of variation in mating patterns and the genetic diversity of a native species. This work has broader implications for conservation as plants have become more vulnerable to antagonists with increasing levels of disturbance, i.e., anthropogenic factors. It will also provide valuable training for a female graduate student, thereby, supporting the goals of NSF to increase diversity in its programs.