Dissertation Research: Molecular Systematics and Chloroplast Genome Evolution of Convolvulaceae

University Of Washington, Seattle WA

Investigators

Abstract

0073396 Olmstead Convolvulaceae, the Morning-glory Family, with some 1600-1700 species are a large group of flowering plants. The members of this family present a rich diversity of morphological characteristics and ecological habitats. Although the family is best known in temperate regions by its weedy representatives (e.g., binding weed) many tropical species are valuable ornamentals and sources of hallucinogenic drugs and purgatives. The "sweet potato" is the World's second most important root crop (> 128 M metric tones per year). Furthermore, many species are used as experimental model organisms in evolutionary and molecular genetics studies (e.g., comparative study of pollination syndromes, research on resistance and tolerance to herbivory and pathogens, biochemical pathways research). Despite this interest, little is certain about the historical relationships among members of the Convolvulaceae. Large plant groups present challenges to systematists interested in understanding the evolution of these groups. Molecular data from chloroplast and nuclear DNA sequences, supplemented with floral and vegetative morphological data, will be used to obtain accurate reconstruction of the relationships within this family. Once resolved, the inferred relationships will be used for following purposes: 1) to assist investigators who seek a historical context for the appearance of particular significant traits among these plants; 2) to analyze the agreement between DNA data and morphological data, with the aim of obtaining a natural classification for this family based on both kinds of information; and 3) to test a series of hypotheses on molecular processes of chloroplast genome evolution in this family, one of the few flowering plant families exhibiting substantial chloroplast genome rearrangements. This investigation will complement other studies being performed in closely related families and will impact the fields of molecular evolution, population genetics, taxonomy, and systematics.