An 8 X 8 diallel cross analysis involving diverse Gossypium hirsutum varieties, namely, LSS, 320 F, H 14, LL 54, J 34, A 102, K 2262 and SA 594 and their nonreciprocal 28 crosses, was conducted for estimating the nature and magnitude of gene effects through component analysis and graphic analysis for ginning outturn, seed index, lint index, fibre length, fibre strength and fibre fineness. Both the additive and dominance variances, were found to be highly significant for all the six characters except fibre strength for which additive genetic variance was nonsignificant. The estimates of dominance variance were relatively higher than the additive variance. The graphic analysis suggested presence of epistatic gene effects in high proportion for fibre strength and in low proportion for G.O.T., seed index, lint index and fibre length, while it was nil for fibre fineness. Suitable breeding procedure (recurrent selection) for exploiting the prevalent types of gene action has been suggested in order to evolve a superior fibre quality cotton variety combining high ginning ability.
