S02 - Session O4 - II - Genetic Diversity of Western Sand Cherry (Prunus besseyi)

Authors: Per McCord *

The USDA National Resource Conservation Service (NRCS) germplasm collection was analyzed for its genetic diversity. The collection included 38 accessions collected from five states and both wild and cultivated populations. Individuals in each accession were fingerprinted with eight SSR markers. The collection was analyzed both as individuals and populations (accessions) via Principle Coordinate Analysis (PCoA). A dendrogram was also created for the 30 accessions with more than five individuals. At the individual level, PCoA suggested the presence of four main clusters. Individuals from cultivated accessions were distributed across all four clusters, while individuals from wild accessions were, with a single exception, present in three of the clusters. When the PCoA was evaluated by State, individuals from the single Minnesota accession were located in a single cluster, and those from Montana (two accessions) were present in all but one cluster, while individuals from Nebraska and North and South Dakota were distributed in all clusters. At the population level, the native accessions were distributed throughout the PCoA plot. Two small clusters of cultivated accessions from more than one state suggested they are derived from historical wild germplasm that was then propagated and distributed. One main branch of the dendrogram consisted exclusively of cultivated accessions. The dendrogram also indicated that some wild accessions from different States are closely related. Overall, the data suggest considerable dispersion of historical collections of Prunus besseyi germplasm via orchards, windbreaks and wildlife plantings. These historical collections are not closely related to some of the more recent accessions collected from the wild. The NRCS collection of Western sand cherry germplasm is quite diverse but could benefit from additional collections from the more southern part of the species range.