Genetic diversity in Persian walnut (Juglans regia L.) seedlings using SSR markers

The first and basic step in identification, conservation, protection of gene resources, genetic research, and breeding programs is determination of genetic diversity in plant material. Using of molecular markers is one of the most important tools in this field. Therefore, the conservation and evaluation of genetic diversity of native plants is necessary. In order to evaluate the genetic diversity of 140 Iranian walnut seedlings, 20 SSR primer pairs were used. The used SSR loci generated 138 alleles. The minimum and maximum number of alleles were for SSR loci WGA69, WGA71, JRHR211298 (five alleles) and WGA202 (nine alleles), respectively. Loci JRHR211298 and loci JRHR217037 produced the minimum and maximum number of effective alleles, respectively. The most value of observed heterozygosity (Ho) generated by loci WGA69. All used SSR loci, showed deviation (P≤0.001) from Hardy–Weinberg. Neigbour-joining dendrogram divided 140 walnut seedlings into five main groups. The study of population structure, with Structure 2.3.1 software, identified two possible groups (k=2). The results of both were largely consistent. The data based on the individual membership share matrix and the Fst rate showed that there was no significant difference between two possible groups.