Heritability study of important bread wheat agronomic traits under drought stress condition using generation mean analysis of Roushan×Kavir cross

Due to Cereal are affected by drought stress in their lifetime. In order to study gene action of bread wheat under drought stress condition, a generation mean analysis was performed using F1, F2 and F3 generations derived from Roushan and Kavir. Generation mean analysis was performed based on joint scaling test. Genetic parameters including additive effect (d), dominance effect (h), additive×additive epistatic effect [i] and dominance×dominance effect [l] were calculated for number of tillers, plant height, awn length, spike length, peduncle length, grain number per spike, grain number per plant, flag leaf length and grain yield. Dominance effect was more important than additive for most of evaluated traits, Therefore, for these traits selection should be made in later generations till desirable genes are fixed. Furthermore, additive×additive epistasis effect, [i], was more important than dominant×dominant effect, [l]. Broad sense heritability for evaluated traits ranged 0.52 to 0.95. While it was ranged 0.32 to 0.76 for narrow sense heritability. Positive heterosis was observed for all traits. selection in later generation in the segregating populations can be effective to improve yield under drought stress condition.