DISSERTATION RESEARCH: The role of reproductive trait shifts in the diversification of Oenothera (Onagraceae)

Washington University, Saint Louis MO

Investigators

Abstract

The evolution and diversification of many flowering plants is linked to the interactions of flowers with the insects and other animals that pollinate them (pollination system), as well as to the ability of a single plant to self-fertilize or cross-pollinate with others of its species (breeding system). These traits vary widely among flowering plant species, but some species are very specialized in the pollinators and the type of fertilization they use. One hypothesis that has been long debated is whether having flowers that are specialized for particular pollinators leads to the evolutionary diversification of more plant species. This project aims to study pollinator and breeding systems in a group of several dozen species in the evening primrose plant family to test this hypothesis. The researchers will use DNA sequences of several genes to reconstruct the evolutionary tree of these evening primroses, and the team will examine details of the pollination process, such as types of pollinators and the nectar and pollen gathered by them. They will then determine whether shifts in pollinator and breeding systems are associated with the evolution of greater numbers of species. The broader impacts of the study include the training of undergraduates in field and laboratory research and the development of collaborations with plant ecologists. The grant supports the research of a female graduate student, who will do outreach work with local high schools and give lectures to conservation groups. Evening primroses are one of many groups of plants that depend upon animal pollinators for their reproduction, and the details of these interactions in the group are important to understand the process of plant reproduction.