Analysis of Genetic Diversity and Population Structure of Spring Bread Wheat (Triticum aestivum L.) from Bangladesh Using SSR Markers

Analysis of genetic diversity and population structure of crop cultivars are the key to design a successful breeding program. In this context, genomic diversity and population structure of 30 bread wheat genotypes were assessed by using 10 simple sequence repeat (SSR) markers. After observation, 50 alleles were recognized from these genotypes, among them, 3 to 9 alleles were observed in each locus with a mean hereditary lushness of 5.0. Generally, markers selection of genomic studies, the informativeness of genotypes can be quantitatively detected by the polymorphism information content (PIC). In the study, the PIC of all genotypes fluctuated from 0.32 to 0.86. Among these utilized markers, the Xgwm186 marker showed the lowest number of alleles (3 alleles) locus^-1, but the maximum PIC value (0.86). In the case of the population structure analysis, all wheat genotypes were grouped into two reconstructed panmictic populations (RPPs). The group RPP I consisted of 17 genotypes of which 15 genotypes were pure and two were admixed. The group RPP II consist of a total of 13 genotypes out of which one variety was admixed. Based on the direction of data entrance, the tree by using Neighbor joining (NJ) method generally shows ˃2 topologies of “tie trees” from a single source of data; however in the current study NJ method showed two groups of genotypes. Among these groups, Group-I consisted of 21 and Group-II consisted of 09 genotypes. Among these studied genotypes, the maximum genetic similarity (94%) was detected in genotypes Barkat and Ananda (similar 47 loci), followed by genotypes Akbar and Inia (92%) and BARI Gom 32 and BAW 1203 (92%). In the case of the principal component analysis (PCA), four clusters were identified among the genotypes by which was similar to the results of STRUCTURE analysis. This study clearly depicted that microsatellite markers are promising in the characterization and differentiation of wheat genotypes, which provides a foundation for the selection of parental material for the genetic improvement of wheat.