The studied parents were crossed in 8x8 half diallel scheme in 2015/2016. Parents and their 28 F1
crosses were evaluated under normal and stress conditions during 2016/2017 in two irrigation levels
experiments. The mean squares were significant for all studied traits. The highest mean values were
detected by parents P3, P2, P1, P5 and P8 for plant height, no of spikelets/ spike, no of spike/ plant,
1000-kernel weight, biological yield/ plant and grain yield/ plant in the combined analysis,
respectively. While, the highest mean values were recorded under combined analysis with crosses
P2xP5 for biological yield/ plant and the cross P6xP8 for grain yield / plant. Mean squares for
combining ability estimates were highly significant for all studied traits. Less GCA /SCA ratios relative
to unity were found for most traits studied traits, revealing that non-additive gene action is more
important than additive and additive x additive types of gene action in controlling these traits.
However, high ratio GCA /SCA exceeded the unity for grain weight/ plant, revealing that additive and
additive x additive types of gene action are more important than non-additive gene action in
controlling this trait. The parental P1 exhibited positive and significant ĝi effects for plant height, No
of spike/ plant, 1000-kernel weight, and biological yield/ plant. The parental P4 exhibited positive and
significant ĝi effects for 1000-kernel weight, and grain weight/ plant. The parental P8 exhibited positive
and significant ĝi effects for biological yield/ plant and grain weight/ plant. The highest desirable SCA
effects were obtained with the crosses P1xP6, P1xP7, P2xP7, P3xP4, P3xP8, P4xP5, P4xP6, P5xP7 and
P6xP8 for grain yield/ plant which exhibited significant and positive ŝij effects. |
