Development of variable microsatellite loci and range-wide characterization of nuclear genetic diversity in the important dryland shrub antelope bitterbrush (Purshia tridentata)

Abstract

Antelope bitterbrush (Purshia tridentata Pursh DC; Rosaceae) is an arid-land shrub that occupies an important ecological niche in various fire-dominated communities across much of the Western United States. Because of its importance as a browse for large mammals and a food source for granivores, P. tridentata is frequently planted by federal agencies in arid-land revegetation. We are currently analyzing the range-wide genetic diversity of this species as part of a larger effort to develop seed movement guidelines. In this study, we describe the development of eight novel nuclear microsatellite loci and characterize the amount and apportionment of range-wide nuclear genetic diversity. The eight microsatellite loci exhibited a high level of polymorphism (13 to 33 alleles per locus) and in general, observed levels of heterozygosity did not deviate form Hardy-Weinberg expectations. An initial screen of 196 individuals from 12 widely distributed populations revealed a moderate amount of genetic differentiation (F_ST = 0.09, P < 0.001). moreover. these loci successfully produced pcr products in cross-species amplifications with two closely related Purshia species. These results demonstrate the utility of these markers and provide useful measures of neutral genetic diversity and population differentiation.

Citation

Horning, M.E.; Cronn, R.C. 2009. Development of variable microsatellite loci and range-wide characterization of nuclear genetic diversity in the important dryland shrub antelope bitterbrush (Purshia tridentata). Journal of Arid Environments. 73: 7-13