Combining Ability for some Quantitative Traits in Sorghum (Sorghum Bicolor l. Moench) Using 9x9 Half Diallel Cross Scheme

This study was carried out in co-operation between Fac. Agric. Benha Univ., and each of (ACSAD) in shandaweel and new valley Research Station (ARC) during 2018 and 2019 season. In the first season, a half diallel cross was made among the nine parents. The nine parents and their hybrids were evaluated in two location i.e. shandweel (L1) and El-Kharga oasis (L2) during 2019 season. The characters studied were plant height (cm), flag leaf area (cm²), leaves dry weight (g), grain yield (g), grain yield (ton/fad) and protein%. Location mean square for all studied trait under study were significant except for grain yield / plant, with mean values in L1  higher than those in L2  for all traits. Mean squares for genotype, parents, F1 hybrid were significant for all traits at both and across locations. Appreciable parent vs crosses mean square were detected for all cases grain yield/plant at both locations as well as the combined analysis, protien % at the first location and grain yield / fed. at the L2. Mean square for parent x location and crosses x locations were significant for all traits. Significant parents vs crosses x location mean squares were obtained in flag leaf area. Regarding grain yield / plant or fed , the parental genotypes P1 and P4 expressed significantly highest mean values compare the other parents. Also, the two crosses P2xP6 and P3xP5 expressed significantly the highest mean values of this trait. The mean squares due to general and specific combining ability were highly significant for all studied traits.GCA/SCA ratio was used as measure reveal the nature of genetic variance involved for all studied traits, all trait exhibited high ratios which largely exceeded the unity were obtained, indicating that large part of the total genetic variability associated with these trait was additive and additive by additive gene effect.The mean squares of interaction between location and both types of combining ability were significant for all studied trait. The parental genotypes (p₅ and P7) expressed significant desirable gi effect for flag leaf area, leaves dry weight, grain yield/ plant and grain yield/ feddan. Meanwhile, it gave insignificant negative for other cases.The most desirable inter and intra allelic interactions were presented by  P₁xP_3, P₂xP_3, P₂xP₅ andP₄xP₅ for grain yield / plant and grain yield/ feddan exhibited significant positive  effects.