An Analysis of Generation Means for Yield and its Component Traits in Bread Wheat

Five generations (P1 P2, F1 F2, and F3) of two wheat crosses, namely, wh 147 × hd 2285 and hd 2009 × wh 147, were raised in randomized block design with three replications during rabi 1985. The means of the five generations recorded for grain yield and its three main component traits, tillers per plant, grains per spike, and 1000-grain weight, were subjected to C-scaling test [1] and live-parameter method [2] to detect epistasis and estimates of m, (d') (h), (i) and (I) parameters. There was evidence of epistasis for all the four characters in both crosses. All three kinds of gene effects (additive, dominance and epistatic) were involved in the inheritance of the characters studied. The additive gene effects were relatively more important than the dominance gene effects for grain weight but a reverse situation was observed for grain yield. Six out of eight cases indicated predominance of complementary epistasis.