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Egyptian Journal of Agronomy http://agro.journals.ekb.eg/ 11 M AIZE (Zea mays L.) is the third-most significant cereal grain in Egypt, although it is susceptible to water stress, which results in substantial losses in both productivity and quality. A set of 100 S1-lines along with their top-crosses using two testers were evaluated under normal and water stress conditions. We used line × tester to evaluate general (GCA) and specific (SCA) combining ability effects for Days to 50% anthesis, Days to 50% silking, and Anthesis silking interval. Results of line × tester analysis showed highly significant differences among parents, crosses vs parents under normal and water stress condition. Both lines and testers showed significant and non-significant differences. Finally, line × tester analysis showed significant differences for Days to 50% anthesis and non-significant differences for Days to 50% silking under normal and water stress condition while, anthesis silking interval trait showed non-significant differences under normal condition and significant differences under water stress condition. Broad sense heritability values for the aforementioned traits were higher under water stress compared to those under normal condition. The high values of broad sense heritability make the selection process easier for the plant breeder and more accurate as the phenotype reflects its genotype. Our findings suggested that dominance genes predominately regulate the aforementioned traits. In conclusion, these S1-lines could be promising as a base for developing early-maturity and drought tolerant hybrids. This will help avoiding water stress events during growing season.

Ten sorghum genotypes (Sorghum bicolor L. Moench) were evaluated at three locations namely; Arab El-Awamer, Shandweel, and El-Fayoum Agric. Res. Stations in 2018 and 2019 growing seasons. Planting time at the three locations during the two years were during the 1 st week of July. The objectives of this study were to determine the performance and stability of ten sorghum across different locations of Egypt. The study was conducted using a randomized complete block design with four replications. Stability analysis for grain yield, 1000-grain weigh, plant height and days to 50% flowering were estimated using Tai's statistical method. A combined analysis of variance emphasized the significant effect of genotypes and locations for all studied traits. There was nonsignificant effect of year for all studied traits, except for 1000-grain weight. The effect of location on Sorghum grain yield and the other studied traits was greater than the effect of year. Hence, testing genotypes under many locations should be done rather than years. Significant effect of genotype x location interaction, suggesting that each genotype differentially responded to the change in the investigated locations. Based on Tai's stability analysis, 3 out of 10 tested sorghum genotypes i.e., (ASH-8 x ICSR-93002), (ASH-9 x ICSR-93002), and (ASH-12 x ICSR-93002) showed average stability and gave high yielding compared to the general mean and are thus the most stable grain sorghum genotypes for grain yield. Generally, Tai's stability method was facilitated the visual comparison and identification of superior genotypes, thereby supporting decisions grain sorghum genotypes for different environments.

Maize (Zea mays L.) is the third most important cereal grain in Egypt (after wheat and rice) but it is vulnerable to water stress which causes lead losses in both yield and quality. In the current study we evaluated 100 S1-lines along with their top-crosses using two testers under normal and water stress conditions. We used line × tester to assess general (GCA) and specific (SCA) combining ability effects for 100-grain weight and grain yield per plot; In addition, we estimated heritability for both traits. Result of line × tester analysis showed highly significant differences among parents, crosses vs parents., In addition, between testers and lines × testers for both traits under normal and water stress condition. The results, lines showed non-significant for 100-grain weight under normal and water stress condition. Grain yield per plot showed non-significant differences under normal condition while it showed significant under water stress condition. Under normal condition, S1-lines 56 and 88 possessed the highest 100-grain weight while, the highest values of 100-grain weight were found in cross combinations including S1-line 29 × SC162 and S1-line 61× TWC352. On the other hand, S1-lines 65 and 68 possessed the highest grain yield per plot while, the highest values of grain yield per plot were found in cross combinations including S1-line 86 × SC162 and S1-line 37× TWC352. Under normal condition, S1-lines 10 and 99 displayed positive and significant GCA effects for 100-grain weight while, S1-line 86 and 55 exhibited the maximum GCA effect for grain yield per plot. Top-crosses including S1-line 29×SC162 and S1-line 75×TWC352 were good specific combiners for 100-grain weight while, the top-crosses including S1-line 29×SC162 and S1-line 78×TWC352 were good specific combiners for grain yield per plot. Heritability in broad sense showed moderate highly estimates for both traits. Our results indicated the preponderance of dominance gene action in controlling both aforementioned traits. In conclusion, these S1-lines are promising to produce drought tolerant inbred line in the future, which may lead to produce drought tolerant hybrid.