Abstract:
Genetic integrity of an accession should be preserved in the conservation of germplasm.
Characterization of diverse germplasm based on a molecular basis enhances its conservation and
use in breeding programs. The aim of this study was to assess the genetic diversity of 169 sorghum
accessions using a total of 6977 SNP markers. The polymorphic information content of the markers
was 0.31 which is considered to be moderately high. Structure analysis using ADMIXTURE
program revealed a total of 10 subpopulations. Neighbor-joining tree revealed the presence of six
main clusters among these subpopulations whereas in principal component analysis, seven clusters
were identified. Cluster analysis grouped most populations depending on source of collection
although other accessions originating from the same source were grouped under different clusters.
Analysis of molecular variance (AMOVA) revealed 30% and 70% of the variation occurred within
and among accessions, respectively. Gene flow within the populations was, however, limited
indicating high differentiation within the subpopulation. Observed heterozygosity among
accessions varied from 0.03 to 0.06 with a mean of 0.05 since sorghum is a self-pollinating crop.
High genetic diversity among the subpopulations can be further explored for superior genes to
develop new sorghum varieties
