Study of Genetic Diversity in Sorghum (Sorghum Bicolar L.) Genotypes using Microsatellite Markers

Sorghum is the fifth degree of importance in the production of cereal after wheat, rice, maize and barley. Genetic diversity estimation of plant material is primary step for identification, protection and conservation of germplasm and breeding programs designing. In order to study of genetic diversity among 10 genotypes of grain sorghum, 10 microsatellite primers were used according to previous studies. Results of the experiment showed that the average polymorphic information content for all primers was 0.48, and the average observed heterozygosity for all Primers was calculated 0.29. The most Shannon index that reflects genetic diversity among populations, obtained in XTxp-312 primer. Also loci XTxp-287 and XTxp-354 had the lowest Shannon index (0.37). XTxp-312 primer had the highest amounts for Shannon index, expected and observed heterozygosity and the largest number of effective alleles. Thus this primer showed more genetic diversity than other primers. In other words, the genotypes showed higher diversity in the case of XTxp-312 primer. Cluster analysis based on molecular data using Jaccard's similarity coefficient and UPGMA method, classified the genotypes of sorghum into four major groups. Based on Principal component analysis results, the first two components PCA1 and PCA2 explained, 50.08 and 10.08 (total 60.15%) of the total variance respectively, indicating that SSR markers distribution across the genome have been relatively good. The overall results of this study showed genetic variation among sorghum genotypes based on microsatellite markers can be used in breeding programs.