Abstract

The F1 hybrids along with the parents were evaluated in field under normal and water stress regimes to determine the nature and magnitude of genetic variances and heritability estimates at Dezful Research Station in Safi Abad, from 2011 to 2012 using RCBD with three replications. Results analysis of variance showed that variations among genotypes were highly significant for all the traits studied under both the regimes. Therefore, variations were partitioned into additive and non-additive components according to Hayman and Hayman & Jinks methods. Based upon the results of tests, simple genetic model was fully adequate for analyzing the data set for all traits except RWC under water stress condition. It was observed that a and b components which are due to additive and dominant gene effects, respectively, were significant for all studied characteristics under both the conditions. Considering the average degree of dominance as well as Vr/Wr graphs revealed that the yield potential traits like plant height, harvest index, RWC and grain yield per plant were controlled by over dominance type of gene action, while traits like ASI and 100kernel weight were under the control of partial dominance with additive type of gene action under both the conditions. Over-dominance for most of the parameters reveals that selection in later generations may be more effective and the selection in early generations will be more effective for the trait which is additively controlled.