الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Drought adversely affects growth and yield of crops to various extents. Growing of drought tolerant crops is a good option. For this reason, a field experiment was conducted to evaluate forty grain sorghum hybrids and their thirteen parental lines under normal and drought conditions (100 and 50% of evapotranspiration (ET)) at Shandaweel Agric. Res. Stat. in 2019 and 2020 growing seasons. The combined analysis of variance over the two treatments was done in 2019 and 2020. The results showed that significant differences were existed among the two irrigation treatments, genotypes (parents and their F1, hybrid) for all studied traits, revealing a large amount of variability among them. Significance of parent vs. crosses indicated the presence of heterotic effects that were highly significant for all the studied traits. Drought susceptibility index indicated that Nine hybrids were the best drought tolerant ones (ATXTSC-20 x 86 EO-361, ATXTSC-20 x TAM-428, ATXTSC-20 x RTX-2817, ICSA-37 x 86 EO-361, ICSA-37 x TAM-428, ICSA-37 x RTX-2817, ICSA-37 x RTX-2895, ATX-407 x RTX-2817 and ATX-407 x TAM-428) The best drought tolerant parental lines were ATXTSC-20, ICSA-37, TAM-428,88V1080, RTX-5646, RTX-2817 and RTX-2895- The best general combiners for grain yield per plant and most of the studied traits were the female lines ATXTSC-20 and ICSA-37 and the male lines 86EO-361 and TAM-428 showed positive and significant general combining ability (GCA) effects under normal and drought conditions. Four crosses (ATXTSC-20 X RTX-2817, ATX-407 X TAM-428, ATX-BON-44 X RTX- 2908 and ATX- 631 X 88V1080) out of the forty hybrid were the best specific combining ability (SCA) under normal and drought conditions. Heterosis related to the better parents and check variety showed that eight crosses were the best hybrids under drought conditions for grain yield and some of the other studied traits.