Evaluation of Some Wheat Genotypes Under Normal and Water Deficit Conditions in North Delta

W ater shortage causes reduction for all the estimated morphological and productivity traits for wheat crop. So, seven bread wheat genotypes consists of three promising lines (115, 117 and 136) and four commercial cultivars (Sakha 95, Sids 14, Gemmiza 11 and Miser 2), which differ considerably in their characters were used as parents with their crosses at the Experimental Farm, Faculty of Agriculture, Kafrelsheikh University, Egypt, during the two successive seasons 2020 /2021 and 2021/2022.The objective was to estimate combining ability and nature of gene action under normal and drought conditions. The results indicated that water deficit decreased the means of all the studied traits for parents and their crosses. The GCA variance was higher than the SCA for all the studied traits under both conditions, except spike length and no. of kernel / spike under both conditions as well as 1000 kernel weight under normal condition, indicating that additive gene effects were more important than non -additive in the expression of the investigated traits. The parents Misr2 and line 136 showed the best desirable GCA effects for earliness, whereas the parents Sakha95 and Line 115 was the best general combiners for grain yield/plant and most of its components under both normal and drought conditions. The two crosses Gemmiza 11x Line 117 and Line 117 xLine 136 were identified as promising specific combiners for earliness, while the cross Misr 2 x Line 136 for improving yielding ability under both conditions. Both additive and dominance genetic components are important in the inheritance of the studied traits. However, the values of (D) were higher than (H1) for all the studied traits, except flag leaf area under drought and Chlorophyll content (SPAD) under both conditions, revealing that the additive gene effects played the major role in the inheritance of these traits.