Analysis of genetic diversity and population structure of some Ethiopian barley (Hordeum vulgare L.) accessions using SSR markers

Abstract

Understanding the genetic diversity of existing genetic resources at the DNA level is an effective approach for germplasm conservation and utilization in breeding programs. However, the patterns of genetic diversity and population structure remain poorly characterized, making germplasm conservation and breeding efforts difficult to succeed. Thus, this study is aimed to evaluate the genetic diversity and population structure of 49 barley accessions collected from different geographic origins in Ethiopia. Twelve SSR markers were used to analyze all accessions and a total of 61 alleles were found, with a mean of 5.08 alleles per locus. The analysis pointed out the existence of moderate to high values of polymorphic information content ranging from 0.39 to 0.91 and the mean Shannon diversity index(I) was 1.25, indicating that they were highly informative markers. The highest Euclidean distance (1.32) was computed between accession 9950 and two accessions (247011 and 9949), while the lowest Euclidean distance (0.00) was estimated between accessions 243191 and 243192. The result of molecular variance analysis revealed that the highest variation was found among accessions (47) relative to within accessions (44) and among geographic origins (9). Cluster analysis grouped the 49 barley accessions into three major clusters regardless of their geographic origin which could be due to the presence of considerable gene flow (2.72). The result of the STRUCTURE analysis was consistent with neighbor-joining clustering and principal coordinate analysis. Generally, this study concluded that the variation among accessions was more important than the difference in geographical regions to develop an appropriate conservation strategy and for parental selection to use in breeding programs. This information will be helpful for barley conservation and breeding, and it may speed up the development of new competing barley varieties.