Assessing genetic diversity in a set of wheat (Triticum aestivum) genotypes using microsatellite markers to improve the yellow rust resistant breeding programs

Evaluation of genetic diversity in plant germplasms is the first and fundamental step in plant breeding programs. For the fact that correct usage of it has lots of benefits, it decreases plants’ damage associated with pests and diseases. In this study, genetic diversity and relationship of 70 genotypes of bread wheat were evaluated by using 60 microsatellite markers. 40 polymorphic markers were selected for clustering and evaluating of genotypes. In total, 309 polymorphic alleles were amplified with an average of 9.26 allele per microsatellite locus. Gene diversity according to Nei for the 42 microsatellite loci varied from 0.4 to 0.91 with an average of 0.74. Polymorphism information content (PIC) value ranged from 0.365 for the barc 87 and the second locus of barc 165 to 0.902 for theXgwm213, with an average of 0.688. Clustering analyses based on Neibour-joinig algorithms and distance coefficient was used and all of the dendrograms indicated that most relative genotypes based on pedigree information, were grouped in the same cluster. In general, they could separate Bolani and MV17 genotypes that are susceptible and resistant parents in most rust breeding projects in the country. The dendrogram result of Rogers distance showed high concordance with available pedigree information of genotypes. Principle components analysis (PCA) also indicates similar results. With stepwise multivariate regression analysis according to the reactions of genotypes to yellow rust and their molecular result, 19 and 17 informative markers were detected for final infection coefficient and area under disease progress curve, respectively.   Key words: Bread wheat (Triticum aestivum), microsatellite markers, genetic diversity, yellow rust.