Research Training Program

Laura Aldrich-Wolfe
University of California - Santa Barbara
Santa Barbara, California

Elizabeth A. Zimmer, Ph.D.
Project Supervisor
Department of Botany

"The RTP not only confirmed my desire to go to graduate school, it also proved to be a summer of hard work, good friends, important connections, and the natural science learning opportunity of a lifetime!"

Establishing the Eurasian Origins of North American Leafy Spurge (Euphorbia esula Complex): RAPD analysis of within- and between-population genetic variation

This project involved a RAPD (Random Amplified Polymorphic DNA) analysis of populations of the Euphorbia esula species complex located in the Ukraine, Russia, Italy and Czechloslavakia to examine genetic variation within and between their populations, as well as attempting to determine the Eurasian origins of E. esula introduced into North America during the last century. Dr. Brunella Bowditch had previously used the same technique to examine genetic variation within North American E. esula populations. This work is part of a larger project of Drs. Bowditch and E. A. Zimmer - in collaboration with scientists at the USDA laboratories in Lincoln, Nebraska - which seeks to elucidate the taxonomy of Euphorbia esula and characterize populations involved in biological control.

Insects and fungal pathogens which serve to control population levels in Europe are absent from North America. Potential biocontrol organisms collected in Austria and Switzerland rejected North American E. esula as a pest. Using genetic information gathered through RAPD analysis of the nuclear genome and RFLPs for the chloroplast genome, the European populations are now being located which are most similar genetically to North American E. esula and the genotypes found within the species complex are being characterized. "Pest" organisms will subsequently be collected from the most similar genotypes and populations. The results obtained by RAPD analysis of E. esula individuals from 4 European populations suggest that Russian and Ukrainian populations are ancestral to and most similar genetically to populations found in North America, and represent the most likely site for collection of biocontrol organisms appropriate for utilization in North America.

This research was supported by a grant from the Smithsonian Women's Committee.