Implementation of a limited set of SSR markers for screening of genetic variability in Latvian and Swedish sour cherry (Prunus cerasus L.) genetic resources collections

Forty-one sour cherry (Prunus cerasus L.) accessions were evaluated using three SSR markers to characterise genetic diversity in the sour cherry genetic resource collections at the Latvia State Institute of Fruit-Growing (LIFG), Dobele, Latvia and the Division of Horticultural Genetics and Plant Breeding at Balsgård, Department of Crop Sciences, Swedish University of Agricultural Sciences (SLU-Balsgård), Sweden, and to test the usability and reliability of a small set of SSR markers for preliminary characterisation of sour cherry germplasm collections. The SSR loci were highly polymorphic with 7-14 alleles per locus. Heterozygosity and Polymorphic Information Content values ranged from 0.750 to 1.000 and 0.748-0.899, respectively, while discrimination power per locus varied from 0.716 to 0.965. Five to thirty genotypes were found in the sour cherry collections for the three tested SSR loci. The combined discrimination power of all loci was effectively 0.994 and 0.999 for the LIFG and SLU-Balsgård collections, respectively. The SSRs used were able to uniquely identify all accessions in the analysed genetic resources collections. The genotype data allowed estimation of genetic diversity and genetic characterisation of accessions in the collections. Genetic similarity analysis showed higher genetic similarity among the Baltic and Scandinavian sour cherry varieties, than between Baltic and Eastern European varieties.