Combining ability and heterosis studies for seed cotton yield and fibre quality traits in hirsutum cotton.

Fifty intra hirsutum hybrids developed by involving five female and ten testers were evaluated to study gene action, combining ability and heterosis. The analysis of variance indicated substantial variability among the experimental material for yield, its contributing components and fibre quality traits. Preponderance of non-additive gene action was obtained for seed cotton yield per plant, majority of its component traits and fibre quality traits. Three parents namely TSH 321, BGDS 1055 and GSHV 177 were identified as very good general combiners for yield and fibre quality traits. The cross combinations TSH 321 x African I-2, and CCH 15-1 x GSHV 177 for seed cotton yield per plant and fibre properties whereas the crosses BGDS 1055 x GSHV 177, TSH 321 x TCH 484-4, SHM 55 x TCH 1819 for seed cotton yield per plant and number of bolls per plant were identified as the best hybrids and these are well suited for exploitation through heterosis breeding as it recorded significant per se, sca effects and standard heterosis for trait as mentioned. Further, the crosses namely SHM 55 x CNH 19, SHM 55 x GSHV 177 and SHM 55 x TCH 486-7 could be recommended for recombination breeding as they satisfied the criteria of the presence of significant gca effects of the parents and non significant sca effects for yield and fibre quality traits. The study also revealed good scope for commercial hybrid development as well as isolation of pure lines among the progenies. [ABSTRACT FROM AUTHOR]