Genetic diversity and population structure analysis of bread wheat (Triticum aestivum L.) germplasms as revealed by inter simple sequence repeat (ISSR) markers

Wheat is one of the most important staple food crops in Ethiopia and elsewhere in the world. Knowledge of its genetic diversity provides breeders a chance to develop new, improved cultivars with desirable traits. In this research the genetic diversity and population structure of 180 bread wheat germplasms representing eight populations was analyzed using 10 Inter simple sequence repeat (ISSR) markers used. Based on diversity indices all the ISSR markers were polymorphic and highly informative. High within-populations genetic diversity with a mean allele values of 1.47, effective alleles of 1.33, Shannon’s Information index of 0.29, Nei's gene diversity of 0.19, and percent polymorphic loci of 80.5% were obtained in this research. Among the populations, those from the International Septoria Observation Nursery (ISEPTON) showed relatively, the highest observed number of alleles (1.47), effective number of alleles (1.33), Shannon’s Information index (0.4) and Nei's gene diversity (0.19). Thus, the ISEPTON lines could be a good source of useful alleles to be used in wheat improvement programs. Analysis of molecular variance revealed that 95% of the total genetic variation resides within populations, while the remaining 5% is accounted to among populations. Clustering using unweighted pair group method with arithmetic mean, principal coordinate analysis and population structure analysis did not group the wheat populations into genetically distinct clusters following their breeding objectives. In the present research adequate polymorphism and reproducible fingerprint profiles were explored from of the genetic structure analysis in the wheat germplasms. The information obtained could thus be useful in future bread wheat breeding programs as well it its sustainable use.