Genetic characterization and population structure of Erysiphe pulchra the causal agent of powdery mildew on Cornus florida in the eastern United States

Author

Christopher Robert Wyman, University of Tennessee

Date of Award

5-2018

Degree Type

Thesis

Degree Name

Master of Science

Major

Entomology and Plant Pathology

Major Professor

Robert N. Trigiano

Committee Members

Denita Hadziabdic-Guerry, Alan S. Windham

Abstract

Cornus florida L. (flowering dogwood) is a deciduous understory tree endemic to the eastern United States. Known for its attractive bracts, C. florida is very popular for its ornamental qualities. After 1995, dogwood powdery mildew caused by Erysiphe pulchra Cooke & Peck reached epidemic levels throughout the C. florida growing region. Initially, both sexual and asexual stages of E. pulchra were regularly observed, but in recent years, the teleomorph has not been seen as often. Fifteen microsatellite loci were used to analyze the genetic diversity and population structure of 174 E. pulchra samples from 10 eastern states. The results of this study indicated low genetic diversity, lack of definitive population structure, and significant linkage disequilibrium within the sampled population. Evidence of a recent bottleneck was also observed. Our results suggest that E. pulchra has become clonal in eastern United States and may be an exotic plant pathogen to North America.

Comments

Portions of this document have been submitted to the Plant Disease journal.

Recommended Citation

Wyman, Christopher Robert, "Genetic characterization and population structure of Erysiphe pulchra the causal agent of powdery mildew on Cornus florida in the eastern United States. " Master's Thesis, University of Tennessee, 2018.
https://trace.tennessee.edu/utk_gradthes/5029