Genetic diversity in Pima ( Gossypium barbadense L.) and advanced interspecific hybrids ( Gossypium hirsutum x Gossypium barbadense ) of cotton germplasm in Ethiopia

This study was conducted to assess the genetic diversity in Pima ( Gossypium barbadense L.) and advanced interspecific hybrids ( G. hirsutum L. x G. barbadense L.) of cotton germplasm in Ethiopia. A total of 26 germplasm were genotyped using 26 polymorphic simple sequence repeat (SSR) markers. A total of 165 polymorphic loci, with a range of 3 to 13 alleles and a mean of 6.35 per marker were detected. About 11% of total alleles were unique alleles in 11 germplasm. The gene diversity varied from 0.39 to 0. 89, while the heterozygosity was in the range of 0 to 1.00. Furthermore, the polymorphic information content of the markers varied from 0.37 (BNL1417) to 0.88 (BNL1672) with an average of 0.68. Among the complete panel of cotton germplasm used in this study, the pairwise genetic distance ranged from 0.08 to 0.94, with an overall mean of 0.61. The UPGMA cluster analysis grouped the Pima cotton germplasm into two cluster groups and the advanced interspecific hybrid cotton germplasm makes one cluster. Principal coordinate analysis indicates that the first three most informative principal coordinates explained 68.4% of the genetic variation. The result evidenced very low to high genetic dissimilarity and overall, a considerable genetic diversity among and within germplasm which could be used to further broaden the genetic base and to enlarge the number of available cotton germplasm.