Phylogenetic Systematics of Moraceae: Inflorescence Evolution and the Origin of a Pollination Mutualism

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Weiblen 0128833 Work by Dr. George Weiblen at the University of Minnesota examines the evolutionary history of the mulberry family (Moraceae) using the DNA sequences from the living members of this ancient lineage of flowering plants. There are more than 1000 species of Moraceae worldwide, including such economically important fruits as figs, mulberries, jackfruit and breadfruit. Among the Moraceae, the figs (species of the genus Ficus) have been a major focus of research in ecology and evolution because of their complex interactions with fig wasps. Specialized wasps that feed on fig seeds are the exclusive pollinators of over 700 species of figs. The mutually beneficial relationship between figs and their wasps has stimulated much research on coevolution, the process by which two species undergo genetic change in response to each other. Ecological studies of fig pollination have advanced our understanding of coevolution, and yet the origins and evolutionary stages leading to fig pollination have remained virtually unknown. This project uses new tools of DNA sequencing and phylogenetic analysis to probe the early history of the mulberry family and to identify the closest relatives of the figs. Field work in the Old World tropics will focus on pollination biology of several Moraceae. Reconstructing patterns of diversification in this way makes it possible to test theories on the origin of the unique fig pollination syndrome, and to improve our understanding of general trends in floral evolution. The project will significantly expand our taxonomic and phylogenetic knowledge of an important branch of the tree of life. Economically significant members of the Moraceae include ornamental and edible figs (Ficus), breadfruit and jackfruit (Artocarpus), paperbark mulberry (Broussonetia), a source of fiber, and breadnut (Brosimum), a major tropical timber. Mulberry (Morus) also plays a key role in the production of silk as the main food source for silk moths. Understanding how these plants are related genetically is important for their sustainable use and conservation. In addition, the research provides an opportunity for advanced graduate training in state-of-the-art molecular techniques combined with museum collections-based approaches to the study of biodiversity.