Precise assessment of diversity in available breeding germplasm helps to preempt epidemics and abrupt environmental changes. Spring wheat germplasm consisting of 84 accessions including cultivars, breeding lines and landraces from various origins was scanned with 44 SSRs. For allele frequencies, allelic patterns, heterozygosity and polymorphism the selected population was divided in three subpopulations i) pregreen revolution (pre1965) ii) postgreen revolution (post1965) iii) postveery (post2000). Alleles produced in pre1965, post1965 and post2000 subpopulations were 115, 144 and 131, respectively. Mean PIC values for pre1965, post1965 and post2000 subpopulations were 0.48, 0.52 and 051, respectively. Allelic patterns showed no locally common alleles in any of the subpopulation. The pre1965 subpopulation had also no private allele, however, average number of private alleles decreased from post1965 to post2000 subpopulation. In case of effective alleles and Shannon’s information index trend was increasing from pre1965 to post1965 and then decreasing from post1965 to post2000. The decreasing trend alarms the reduced genetic diversity in wheat varieties developed after 2000. PCA and cluster analysis didn’t clearly differentiated subpopulations, though pre1965 genotypes showed higher genetic distance from post1965 and post2000 subpopulations. The decreasing measures of genetic diversity in post2000 wheat genotypes should be a concern for wheat breeders, therefore, all sources of broadening genetic diversity should be exploited.
Keywords: Wheat, genetic diversity, SSR, allelic patterns
