Conservation Genetics of White Ash on the Vassar College Ecological Preserve

Professor Mark Schlessman

Introduction and spread of the emerald ash borer (EAB) have made assessments of genetic diversity in North American ash trees an urgent priority. In the fall of 2015, Biology professor Mark Schlessman’s Evolutionary Genetics class used expressed sequence tag simple sequence repeat (EST-SSR) markers to examine genetic diversity of 34 white ash trees on the Vassar College Ecological Preserve. Allelic richness ranged from two to 19 per locus. For eight of the 14 loci studied, the frequency of heterozygotes was significantly lower than expected under Hardy-Weinberg equilibrium, suggesting the possibility of inbreeding. While these results are similar to those obtained from several studies of European ashes, and one study of North American green ash, there are as yet no comparable studies of North American white ash. Population genetic data such as ours may be used to select particular trees for pesticide treatments, and to search for genetic markers associated with resistance to EAB.