Genetic relationship of diploid wheat (Triticum spp.) species assessed by SSR markers

Genetic diversity of 139 accessions of diploid Triticum species including Triticum urartu, Triticum boeoticum and Triticum monococcum was studied using 11 SSR (simple sequence repeats) markers. A total of 111 alleles with an average of 10 alleles per locus were detected. The polymorphism information content (PIC) of each SSR marker ranged from 0.30 to 0.90 with an average value of 0.62. Among the three Triticum species T. urartu had the highest number of total alleles (Na = 81), private alleles (Npa = 15) and showed higher genetic diversity (Hex = 0.58; PIC = 0.54). The genotypes from Turkey exhibited the highest genetic diversity (PIC = 0.6), while the least diversity was observed among 4 Georgian accessions (PIC = 0.11). Cluster analysis was able to distinguish 139 wheat accessions at the species level. The highest genetic similarity (GS) was noted between T. boeticum and T. monococcum (GS = 0.84), and the lowest between T. urartu and T. monococcum (GS = 0.46). The grouping pattern of the PCoA analysis corresponded with cluster analysis. No significant differences were found in clustering of T. urartu and T. monococcum accessions with respect to their geographic regions, while within T. boeoticum species, accessions from Iran were somewhat associated with their geographical origin and clustered as a close and separate group. The results from our study demonstrated that SSR markers were good enough for further genetic diversity analysis in einkorn wheat species.