Gene action, combining ability and standard heterosis for seed cotton yield and fibre quality components in upland cotton

Twelve parental genotypes and twenty F₁ hybrids developed in a Line x Tester fashion were used in the present study to estimate gene action, combining ability and standard heterosis for eleven quantitative and five quality traits in cotton. All the traits studied exhibited greater SCA variance than GCA except days to fifty per cent flowering suggesting that these traits are controlled by dominant gene action. Among the parents used, SVPR 2 and TSH 325 were detected with higher general combining ability for seed cotton yield and should be given importance while developing hybrids or recombinants. The hybrids namely SVPR 2 x TSH 325, SVPR 2 x Suraj and GJHV 370 x PBH 116 were identified as the best hybrids for seed cotton yield and SVPR 2 x TCH 1828 for fibre properties and recommended for heterosis breeding. Besides, the hybrid between GJHV 370 x CPD 1702 was suggested for recombination breeding for earliness and ginning percentage as it fulfilled the criteria of non-significant sca effects for hybrid and significant gca effects for respective parents.