Diallel cross study for estimating genetic components underlying wheat grain yield

Abstract

In order to analysis genetic control of grain yield, five cultivars and their F2 diallel crosses were sown in two locations of Shiraz and Zarghan, Iran. The traits of interest were number of grains per spike (GN), weight of grains per spike (GW), number of spikelet per spike (SN), spike length (SL), 1000-grain weight (TGW) and grain yield per plant (GY). The significant variances due to general (GCA) and specific (SCA) combining abilities indicated that both additive and non-additive components were involved in genetic control of traits. The GCA × location was only significant for GW. The Baker ratio implied the higher importance of additive variances. Graphical analysis of Hayman showed that gene action for all the traits was of partial dominance type. The environmental sensitivity analysis indicated heterogeneity among cultivars and their progenies for GW and that except Marvdasht, most of cultivars were relatively sensitive to the environmental conditions. The SCAs revealed that selection among progenies of Crossadl × Darab2 cross would be efficient for increasing GY. The GCA estimates revealed that the cultivars Cross adl and Marvdasht for GY, Cross adl and Shiraz for SN and SL and Cross adl for all traits were the best combiners.