Heterosis and combining ability for grain yield and its components in induced sorghum mutants

Abstract

Heterosis, general combining ability (GCA) and specific combining\nability (SCA), and their effects were studied for five major traits in\na design II mating system in pure sorghum lines obtained by induced\nmutation. Significant genotype effect was detected for all traits. GCA\neffects were highly significant for all traits studied. Effects due to\nSCA were of less magnitude except on plant height. Some parents were\nidentified having high GCA for grain yield and low or negative GCA for\ndays to anthesis, which were considered as good combiners. The ratio of\ngeneral combining ability to specific combining ability indicated that\nadditive gene effect was the predominant type of gene action for most\nyield contributing traits. High positive heterosis for grain yield and\nits components, including days to anthesis and plant height, as found\nfor more than half of the hybrids studied. Some pure lines evaluated\nmay be used directly as male parents of hybrids and as breeding lines\nfor incorporation into selection programs. The results demonstrate for\nthis set of genotypes the considerable potential that exists for\nimproving the yield performance of sorghum in Western Africa.\nImportance of genotype x environment interaction underlines the\nnecessity of evaluating breeding materials under a broad range of dry\nland conditions. This research would assist decisions on parental\nselection for more extensive study of heterozygosity involving large\nnumbers of genotypes.