Chloroplast DNA Phylogeny of Basal Angiosperms

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9727025 Olmstead Dr. Olmstead's research will address a problem that has confounded botanists for several hundred years: the pattern of early diversification of flowering plants (angiosperms). This research project should help us to understand what these plants may have looked like and what course of evolution in floral and vegetative features may have taken. In many respects this is the greatest question in flowering plant systematics. Three prior DNA-based studies examining individual genes have yielded conflicting results or have been unable to resolve relationships among the extant representatives of lineages that were diverged approximately 100 million years ago. The experimental approach will be to determine DNA sequences for 17 chloroplast genes totaling approximately 13,000 nucleotides for each of approximately fifty plant species chosen to represent previously identified critical lineages of the basal angiosperms. This approach will provide a three-fold increase in the data currently available to help solve the problem and should be sufficient to produce resolution. Much of the required material for the research has already been gathered, and additional sampling will be achieved by cooperation with other researchers and curators at botanical gardens.