Comparative analysis Crimean, Moldavian and Kuban Persian walnut collections genetic variability by SSR-markers

To date, the current issue is the history of the walnut spreading after last glacial maximum (LGM) as well as the role of human in this process and his impact on the population structure. Large-scale studies of the walnut loci microsatellite diversity were carried out by various research teams and include a wide range of potential refugia and natural walnut stands, plantations and collection samples from different regions. But resulted map of walnut distribution and genetic structure has a blank spot including large territory of northern black sea basin countries - Republic of Crimea, Republic of Moldova and southern part of Russia. In this regard, we selected a total of 62 samples from the collections of the Nikita Botanical Gardens, North Caucasian Federal Science Center of Horticulture Viticulture & Winemaking (NCFSCHVW), the private Moldovan collection and analyzed by 11 microsatellite loci. All markers have showed a high level of polymorphism, the number of alleles (Na) varied from 6 to 16 per locus. The observed heterozygosity (Ho) was 0.44 to 0.86 with an average value of 0.67 and was lower than the effective (He) for all loci, with the exception of WGA376. According to the principle coordinates analysis, and Bayesian analysis, the Kuban cultivars is genetically distant from the Crimean and Moldavian, as well as Central Asian germplasm. The differences between the genotypes from Crimea and Moldova are not so significant. According to obtained data, we can conclude that the source of genetic diversity in the Kuban belongs to one of the walnut diversity centers found during previous molecular genetic studies. It could be the Transcaucasus, as the most territorially close source or South-West Asia.