In this study, twelve wild Iranian walnut (Juglans regia L.) populations were screened using ten simple sequence repeat (SSRs) markers. Based on our results, a high level of genetic diversity was observed among and within populations with the number of alleles per locus ranging from 6 to 11, with a total of 83 alleles and 8.3 alleles and 4.9 effective alleles on average per loci. In individual populations, the observed heterozygosities ranged from 0.525 to 0.713 with an average of 0.659. The average genetic distance among populations equaled 0.452, ranging from 0.094 to 0.73. Cluster analysis, done by UPGMA, grouped all populations into four main groups according to their genetic distances. These results provide evidence of the high potential of Persian walnut populations of Iran for breeding programs.
