Combining ability studies in cotton (Gossypium hirsutum L.) for yield and fibre quality parameters

Abstract

Combining ability is mostly used by breeders to identify and select appropriate parental genotypes to produce the larger progeny of new combinations through their hybridization. The objective of this research was to estimate general combining ability of parents and specific combining abilities of F1 hybrids, to identify suitable parents and hybrids for yield and its contributing traits, fibre quality parameters. Nine genotypes and 20 F1 hybrids derived by crossing the parental genotypes in L x T design were sown in randomized complete block design. The ratio of σ2 GCA/σ2 SCA was smaller than zero for all the characters indicating predominance of non-additive gene action (dominant or epistasis) in the inheritance of investigated traits except lint index. The line × tester interactions made greater contribution to the total variance for most of the traits i.e. boll number per plant, boll weight, lint index, lint yield, micronaire, elongation per cent and seed cotton yield. From this study, it is evident that the genotypes TCH 1716 and L 765 were found to the potential combiners for yield and most of the fibre quality parameters as well. Further, the cross combination GSHV 179 x L 765 was found to be the best for commercial exploitation.