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The 2010 ASHS Annual Conference

3203:
Genetic Diversity of Flowering Dogwood Maintained Despite Massive Mortality Caused by Dogwood Anthracnose

Thursday, August 5, 2010: 2:00 PM
Springs A & B
Denita Hadziabdic, Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN
Benjamin Fitzpatrick, Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN
Xinwang Wang, Texas AgriLife Research and Extension Center, Texas A&M System, Dallas, TX
Phillip A. Wadl, Research Assistant Professor, Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN
Timothy A. Rinehart, USDA ARS SHL, Poplarville, MS
Bonnie H. Ownley, Univ of Tennessee, Knoxville, TN
Mark Windham, Entomology & Plant Pathology, University of Tennessee, Knoxville, TN
Robert Trigiano, Univ of Tennessee, Knoxville, TN
Flowering dogwood (Cornus florida) populations recently have experienced severe declines caused by dogwood anthracnose. Mortality has ranged from 48 to 98%, raising the concern that genetic diversity has been reduced significantly. Microsatellite data were used to evaluate the level and distribution of genetic variation throughout much of the native range of the tree. Genetic variation in areas affected by anthracnose was as high as or higher than areas without die-offs. We found evidence of four widespread, spatially contiguous genetic clusters. However, there was little relationship between geographic distance and genetic difference. These observations suggest that high dispersal rates and large effective population sizes have so far prevented rapid loss of genetic diversity. The effects of anthracnose on demography and community structure are likely to be far more consequential than short-term genetic effects.