Genetic Diversity and Population Structure Analysis of Bread Wheat (Triticum aestivum L.) Germplasms as Revealed by ISSR markers

Abstract Wheat is one of the major food crop in Ethiopia and elsewhere in the world. Genetic diversity provides breeders chance to create new, improved varieties with desirable traits. In this study genetic diversity and population structure of 180 bread wheat germplasms representing eight populations were analyzed using ten Inter Simples Sequence Repeat (ISSR) marker. Based on diversity indices all the ISSR markers were polymorphic and highly informative to describe genetic diversity and population structure of the crop. High within-populations genetic diversity with a mean of alleles of 1.47, effective alleles of 1.33, Shannon’s Information index of 0.29, Nei's gene diversity value of 0.19, and percent of polymorphic loci (PPL) of 80.5% were reviled. Among the populations, international Septoria observation nursery (ISEPTON) showed relatively 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, ISEPTON lines could be good source of useful alleles to be used in wheat improvement programs. Analysis of molecular variance (AMOVA) revealed that 95% of the total genetic variation resides within populations, and 5% was accounted for the among populations variation. Clustering using Unweighted pair group method with arithmetic mean (UPGMA), Principal coordinates analysis (PCoA) and population structure analysis did not group the wheat populations into genetically distinct clusters following their breeding objectives. Adequate polymorphism and reproducible fingerprinting profiles were explored form the genetic structure analysis of the wheat germplasms. The information obtained could be useful in future bread wheat breeding programs, and also its conservation.