NULL

NULL

NULL

NULL

NULL

The experiments were conducted in the farms of Fac. Agric. Assiut Univ. in clay and new reclaimed soils. The plant materials consisted of 41 sorghum entries including 30 F1 hybrids, five restorer lines and six B-lines (cytoplasmic male sterility lines). The testers were crossed to lines in season 2013. The 41 entries were evaluated in 2014 and 2015 seasons under well-watered and drought stress at two locations represent clay and reclaimed soils (eight environments). Surface and drip irrigation systems were applied in the clay and reclaimed soil, respectively in order to carry out the well-watered and drought stress conditions. The combined analysis of variance indicated significant (p≤0.01) differences among the 8 environments, and most of the variability was for environments. Mean squares of genotypes, lines, testers and crosses, and their interaction with environment were significant (p≤0.01) for all traits reflecting sufficient genetic variability, the presence of both additive and non-additive, and assessment of combining ability could be proceeded. The standard deviation of the additive variance under the eight environments was less than the dominance variance for all traits. This indicates that the additive variance was more stable than the dominance one with differences in environment. Except few cases, results indicated that both additive and dominance variances were larger under well-watered than under drought stress, and under clay soil than under reclaimed soil for all traits. The dominance variance was larger than the additive one in 58 of 64 cases of all traits under study. The combined data indicated that the additive variance across environments was larger than the dominance variance only for plant height, however, the dominance variance was larger than the additive one for days to blooming, panicle weight, panicle length, panicle width, grain yield /plant, threshing % and seed index. There was no line or tester could be considered the best combiner for all traits, however line no.3 was the best combiner for most traits. The combinations; F3×T3, F3×T4 and F1×T4 could be considered the best in grain yield / plant and showed significant better parent heterosis.

The experiments were conducted in the farms of Fac. Agric. Assiut Univ. in clay and new reclaimed soils. The plant materials consisted of 41 sorghum entries including 30 F1 hybrids, five restorer lines and six B-lines (cytoplasmic male sterility lines). The testers were crossed to lines in season 2013. The 41 entries were evaluated in 2014 and 2015 seasons under well-watered and drought stress at two locations represent clay and reclaimed soils (eight environments). Surface and drip irrigation systems were applied in the clay and reclaimed soil, respectively in order to carry out the well-watered and drought stress conditions. The combined analysis of variance indicated significant (p≤0.01) differences among the 8 environments, and most of the variability was for environments. Mean squares of genotypes, lines, testers and crosses, and their interaction with environment were significant (p≤0.01) for all traits reflecting sufficient genetic variability, the presence of both additive and non-additive, and assessment of combining ability could be proceeded. The standard deviation of the additive variance under the eight environments was less than the dominance variance for all traits. This indicates that the additive variance was more stable than the dominance one with differences in environment. Except few cases, results indicated that both additive and dominance variances were larger under well-watered than under drought stress, and under clay soil than under reclaimed soil for all traits. The dominance variance was larger than the additive one in 58 of 64 cases of all traits under study. The combined data indicated that the additive variance across environments was larger than the dominance variance only for plant height, however, the dominance variance was larger than the additive one for days to blooming, panicle weight, panicle length, panicle width, grain yield /plant, threshing % and seed index. There was no line or tester could be considered the best combiner for all traits, however line no.3 was the best combiner for most traits. The combinations; F3×T3, F3×T4 and F1×T4 could be considered the best in grain yield / plant and showed significant better parent heterosis.

The present work was conducted to study the effects of late planting on the performance of Egyptian cottons and to obtain information concerning the genetic control of earliness, lint yield/plant, lint% and lint index. Half diallel crosses among seven Egyptian cultivars were evaluated in the F2-generation under early and late planting conditions for two seasons. The reduction% in lint yield/plant caused by late planting was very high and reached 73.92% for the parents and 68.27% for the F2-populations. Both additive and non-additive gene effects were involved in the inheritance of days to first flower, earliness index, lint yield/plant, lint% and lint index, but the non-additive was much larger than the additive gene effects. Epistatic gene effects were found in the earliness traits and lint index in the second season, lint% and lint yield/plant in early planting in the second season. The graphics of Wr/Vr analysis for lint yield indicated that the distribution of the parents around the regression line was not consistent in both of early and late plantings in the two seasons. The genetic parameters indicated unequal distribution of dominance and recessive genes in the parents for all traits. The non-additive effects of genes were reflected in the departure from broad to narrow sense heritability. Therefore, pedigree and recurrent selection methods could be effective in late segregating generations. The promising F2-populations were “Giza 90 x Giza 80”, “Giza 90 x Giza 88”, “Giza 90 x Giza 86” and “Giza 86 x Giza 80”.

ABSTRACT A half diallel set of crosses of seven Egyptian cotton cultivars (G. barbadense L.) was conducted and evaluated in the F2-generation for two years under early and late planting to study the effects of planting date on the performance and type of gene action controlling seed cotton yield, number of bolls, boll weight and seed index. The combined reduction due to late planting in seed cotton yield/plant was 71.21% for the parents and 65.17% for the F2-generations. The average reduction in number of bolls/plant, boll weight and seed index was 69.72, 9.11, and 12.67% for the parents, and 63.42, 9.95 and 12.37% for the F2-generations; respectively. Both of additive and non-additive effects of genes were operating in the inheritance of all traits, and the non-additive effects were very large compared to additive gene effects. Epistatic gene effects were found in all traits in the second season. The dominant and recessive genes were not equally distributed among the parents. The graphics of Wr/Vr analysis indicated that the distribution of the parents around the regression line was not consistent from early to late planting and from year to year for seed cotton yield/plant and number of bolls/plant. Negative intercept of the regression line to the Wr axe was found for seed cotton yield in three cases and for number of bolls/plant in all cases, indicating over-dominance. The non-additive effects of genes were reflected in the departure of narrow from broad sense heritability in seed cotton yield, number of bolls/plant and boll weight. Therefore, pedigree and recurrent selection methods could be effective in late segregating generations of these material. The promising F2-populations for the studied traits to select lines adapted to early and late plantings were Giza 90 x Giza 86, Giza 92 x Giza 86, Giza 88 x Giza 86 and Giza 86 x Giza 80.

A half diallel set of crosses among seven wheat parents (Triticum aestivum L.) was conducted and evaluated in the F2-generation under drought stress and normal irrigation conditions. The reduction % caused by drought stress in the F2-populations was low for days to heading (DH) (2.55%) and harvest index ( HI) (1.05%), moderate for plant height (6.12%), spike length (8.89%) and 100 GW (6.64%), and high (15.53%) for number of spikes/plant (NS/P) and grain yield/plant (GY/P) (18.52%). Four promising F2-populations were obtained; "Om 2 x Sids 13" gave the highest GY/P under both of drought and normal irrigation environments (18.03 and 22.0 g), "Om3 x Sids 13" gave good yield under drought stress (16.13 g) and was responsive to good environment (normal irrigation) (20.33 g), "Om 2 x Om 3" and "Om 2 x Sids 4" gave good yield under drought stress and were responsive to good environment. The graphical analysis of Wr and Vr indicated that, the distribution of the parents around the regression line was not consistent for drought stress and normal irrigation, for plant height, NS/P and HI, and consistent for the other traits. The average degree of dominance was partial for all traits except for HI and 100 GW under drought stress, which showed complete dominance. The results indicated that both additive and dominance effects of genes were involved in the inheritance of all traits. The dominance variance "H1" was larger than the additive one "D" under both environments and "H1" increased under drought stress. Non-allelic gene interactions (epistasis) were involved in the inheritance of all traits except days to heading and plant height under normal irrigation. Earliness, NS/P and 100GW showed positive significant correlations with GY/P, therefore, these traits should be considered when selection practiced for GY/P in the promising populations of these materials either under drought stress or normal irrigation. These results suggest that pedigree and recurrent selection methods could be effective to improve new wheat lines from the above mentioned promising populations under both environments.