Genetic relatedness of sweet cherry (Prunus avium L.) cultivars from Ukraine determined by microsatellite markers

Microsatellite (SSR) markers were used to characterise 23 sweet cherry cultivars of Ukrainian, and four cultivars of non-Ukrainian, origin. To assess their genetic diversity and relatedness, 11 pairs of primers were applied to microsatellite loci, resulting in amplification of 66 SSR alleles. The mean value of the number of different alleles, and the polymorphic index content, amount to 7.333 and 0.700, respectively, demonstrating a significant genetic diversity of the investigated sweet cherry cultivars. Four highly polymorphic SSR loci (EMPAS02, EMPAS06, PceGA34, UDP98-412), which belong to the list recommended by the European Cooperative Program for Plant Genetic Resources, can be used as a minimum genetic marker set for identification of the majority of the studied cultivars; however, for successful discrimination of the most similar cultivars, more markers, located on all chromosomes of sweet cherry, appear to be necessary. Application of unweighted variable-group method using averages clustering allowed elucidation of the relatedness among the sweet cherry varieties, and showed that the Ukrainian cultivars combine genetic material of local, western European, and probably Caucasian origin; however, the origin of several cultivars still remains unclear, and should be studied additionally.