Assessment of gene action and combining ability for fibre and yield contributing trais in interspecific and intraspecific hybrids of cotton

Abstract

Combining ability analysis was performed in order to identify high-yielding genotypes and hybrids. Six lines were crossed with three testers using a line × tester mating design. General combining ability (GCA) of parents, specific combining ability (SCA) of hybrids and gene action for several yield components and fibre were studied in the experiment. Additive gene action was observed in most traits except bolls/plant, sympodia/plant, monopodia/plant, total nodes, seed index, lint/seed, staple strength and seed cotton yield/plant which were influenced by non-additive gene action. GCA revealed that Giza-7 was a good general combiner for staple length, staple strength, seed index, boll weight, bolls/plant and monopodia/plant and BH-167 was good for ginning outturn (GOT) and sympodia/plant. Results of SCA values for hybrids indicated, that the cross Giza-7 × MNH-886 was a superior specific combiner for staple length, monopodia/plant, staple strength and seed cotton yield/plant; CIM-554 × CIM-557 for boll weight, sympodia/plant and lint weight/boll; BH-167 × MNH-886 for GOT and bolls/plant. Selection of such hybrids and good general combiners could be further exploited for yield improvement.