Genetic Diversity and Population Structure of Plum Accessions from a Romanian Germplasm Collection Assessed by Simple Sequence Repeat (SSR) Markers

Abstract

In Romania, Prunus genetic resources are held in collections located mainly in research and development institutes or in fruit growing stations. A possible disadvantage of the utilization of these resources for genetic studies and also for breeding programmes is the lack of reliable data for correct identification and characterization of accessions. In this study, 27 plum accessions from Râmnicu-Vâlcea Fruit Research Station, Romania, were assessed using nine SSR markers generating a total of 134 distinct alleles, with an average of 14.89 alleles per locus. Differentiation between the Romanian plum cultivars and international reference cultivars was low, but significant, for all the nine loci (Fst = 0.012; P < 0.0001). Plum accessions were grouped in two clades, both including old and newly developed Romanian cultivars and also international reference cultivars, according to an UPGMA dendrogram. Bayesian analysis of genetic structure revealed significant admixture among examined accessions while principal coordinate analysis performed on the molecular data illustrated a substantial dispersion of old and newly developed Romanian plum accessions in the three-dimensional PCoA scatter plot. These results could make them attractive for future breeding programs and long-term conservation strategies based on identified genetic dissimilarities.