Evaluation of Flowering Cherry Species, Hybrids, and Cultivars Using Simple Sequence Repeat Markers

Flowering cherries belong to the genus Prunus, consisting primarily of species native to Asia. Despite the popularity of ornamental cherry trees in the landscape, most ornamental Prunus planted in the United States are derived from a limited genetic base of Japanese flowering cherry taxa. A diverse collection of ornamental Prunus germplasm is maintained at the U.S. National Arboretum as part of an ongoing flowering cherry improvement program, but the genetic backgrounds of many trees are unclear. We characterized this germplasm using five simple sequence repeat (SSR) primer pairs, including one chloroplast primer pair. These primers generated 140 unique alleles that were used to assess genetic relationships among species, hybrids, and cultivars in this collection. We found that these markers followed expected Mendelian inheritance from parents to progeny in controlled hybridizations. In general, species clustered according to published taxonomic groupings, including a distinct separation of the ornamental cherries (Prunus subgenus Cerasus section Pseudocerasus) from other subgenera. Individual accessions of several taxa did not cluster with other samples of the species, indicating possible misidentification or interspecific combinations. The resulting information will be useful in guiding decisions on breeding methodology and germplasm preservation.