Genetic diversity in sorghum (Sorghum bicolor L. Moench) accessions using SNP based Kompetitive allele-specific (KASP) markers

Genetic diversity analysis is an important component in conventional and marker-assisted breeding. The objective of this study was to assess the level of genetic diversity among 100 sorghum accessions, which were selected randomly from the Sorghum National Germplasm Bank maintained at Agricultural Research Council, South Africa. A total of 136 Kompetitive Allele-Specific PCR (KASP) markers were used in this study. The KASP markers were previously derived from single-nucleotide polymorphic (SNP) analysis of the world-wide sorghum accessions by other research groups. A total of 110 KASP markers were polymorphic and recorded an average polymorphic information content (PIC) value of 0.3, which indicated high level of discrimination of the markers. The markers had an average gene diversity and observed heterozygosity of 0.3 and 0.10, respectively. Analysis of molecular variance revealed a significantly high variation among accessions (83% and 89%) than within accessions (10% and 11%) based on breeding status and geographic origin, respectively. Genetic distance varied from 0.0 between SA0672 and SA0673, SA1282 and SA0670 to 0.57 between Hakika and SA1442 with an average mean of 0.30. The dendrogram and model-based population analysis identified three and four distinct groups in 95 sorghum accessions, respectively. These results imply the presence of genetic diversity and lack of genetic bottleneck within the National Sorghum Germplasm Bank, which could be highly relevant for sorghum breeding and germplasm maintenance