Assessment of heterosis and combining ability for fibre yield, its contributing and quality traits in Bt BGII upland cotton (Gossypium hirsutum L.)

Heterosis breeding is one of the most practical and accomplishing tool for cotton improvement. In this context 32 intra-specific hybrids derived from eight lines and four testers were evaluated on multi-location to assess heterosis and combining ability for seed cotton yield and its contributing traits. Significant heterosis was observed in the crosses NH-2260 BGII x NH-2236 BGII, NH-2202 BGII x NH-2289 BGII and NH-2224 BGII x NH-2289 BGII for seed cotton yield and yield contributing characters over a better parent and best check. Combing ability analysis suggested the preponderance of non-additive gene action for most of studied traits. The line NH-2230 BGII and NH-2260 BGII were observed to be good general combiners for seed cotton yield and its contributing traits and the tester NH-2289 BGII was identified as the best general combiner for seed cotton yield and its contributing characters, ginning outturn, lint index. The hybrid NH-22105 BGII x NH-2236 BGII exhibited a significant positive SCA effect for seed cotton yield per plant.