LAUSR

Knowledge of genetic diversity among sorghum genotypes is essential for their efficient utilisation in plant breeding schemes and effective conservation. The objective of this study was to assess the level of genetic diversity present among South African sorghum genotypes using phenotypic traits. Ninety-eight sorghum accessions were phenotyped at two sites during the 2012 growing season. Experiments were laid out in an alpha lattice design with three replications. Data were collected on eight quantitative and six qualitative traits, and subjected to principal component and hierarchal cluster analyses. A dendrogram was constructed using the unweighted pair group method with arithmetic mean. Grain yield showed a positive and significant association with plant height, panicle width and rachis number but was negatively associated with panicle exsertion. The principal component analysis revealed three important principal components that accounted for 88.0% of the total variation observed among genotypes across locations. Principal components 1, 2 and 3, respectively, correlated with plant height, grain yield and panicle weight. A dendrogram revealed three main clusters of genotypes. The most diverse accessions identified were 4277, 2934, 5097, 4909 and 4303, which are useful for breeding. The diversity observed among the sorghum genotypes could be useful in improvement of sorghum for various traits.