Authors:M. Naghavi, A. Ebrahimi, M. Sabokdast, and M. Mardi
In this study, simple sequence repeat (SSR) markers were used to investigate the genetic diversity and evolutionary relationships among 74 barley accessions; 15 landraces (Hordeum vulgare) and 59 wild accessions (twenty-one Hordeum spontaneum, ten Hordeum bulbosum, thirteen Hordeum murinum and fifteen Hordeum marinum). A total of 66 alleles were detected at 12 SSR loci, with an average of 5.5 alleles per locus in the entire samples. The average number of alleles (4.2) per locus was higher in H. vulgare and H. spontaneum, reflecting more genetic diversity within these two species compared with the other species. All index values of genetic diversity revealed that there was higher genetic diversity within H. vulgare landraces than within the wild species, indicating that cultivation unlikely to have caused a loss of genetic diversity in cultivated barley compared with its wild relatives. Analysis of molecular variance (AMOVA) revealed that 31% of the total observed variation was accounted for among species. Based on neighbor-joining clustering, the five species were classified into three main groups: (i) all accessions of H. marinum and H. bulbosum plus two accessions of H. murinum; (ii) H. vulgare and H. spontaneum accessions, in small, separated groups; and (iii) the remaining accessions of H. murinum. Principal coordinates analysis (PCoA) for SSR data also supported the neighbor-joining clustering. These results have important implications for barley germplasm characterization, improvement, molecular systematics and conservation.