Collaborative Research: Sex Ratio Evolution in Ephemeral Demes of a Gynodioecious Plant

Vanderbilt University, Nashville TN

Investigators

Abstract

0078531 McCauley Gynodioecy is a condition in plant populations in which hermaphroditic and female individuals coexist. It arises when a mutation (called a cytoplasmic male sterility (CMS) factor) causes hermaphrodites to lose male function, with a concurrent increase in seed production. Understanding how gynodioecy persists is an ongoing question in the field of plant population biology. This project will combine molecular genetic markers and genetic crosses to ask how many different CMS factors exist in small natural populations of Silene vulgaris, and how those factors are distributed spatially. This will be combined with mathematical and computer models in order to understand how the extinction and recolonization of local populations influences the evolution of gynodioecy. This project will be relevant to several broader scientific issues. First, CMS factors are an example of "selfish DNA". The studies of S. vulgaris will be one of the few to link molecular markers to selfish elements in nature. Second, the study of the genetics of small and fragmented populations is significant for conservation biology. This study of S. vulgaris will yield general information about genetic processes in small populations. Finally, gynodioecy is important for agriculture because it is used as a tool by plant breeders for increasing crop yield.