الفهرس 
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Abstract
A set of 10 bread wheat genotypes were used in the current study. This set comprised of. These AIL lines were derived from different crosses and selected under different environments through shuttle breeding approach in CIMMYT. These 10 genotypes were sown in a strip plot design with 3 replications. The aforementioned genotypes were grown during two growing seasons (2017\ 2018 and 2018 \2019) the Agricultural Research Station, Faculty of Agriculture, Assiut University, Egypt. Both optimal and drought conditions were 2 Egyptian cultivars, and 8 advanced inbred lines (AIL) obtained from CIMMYT applied. In the optimal condition, genotypes were irrigated regularly; however, in the drought condition, four irrigations were skipped, two during vegetative growth and two during flowering stage.
A – Morphological traits:
1- Plant height
The highest plant height of the AIL134 and AIL108 genotypes have been found, while separate and combined variance analysis revealed significant differences.
The height of the plant due to drought decreased slightly in the first, second year and combined 10.51, 7.29, 8.79, respectively.
2- Number of tillers and Number spikes of plant
Drought susceptibility index varied from year to year and in combined for most of the 0.12 genotypes. For the genotype AIL108 in the first year, 0.21 for AIL112 in the second year, and 0.48 for AIL103 in combined. For number of tillers as for number of spikes of plant it was Drought susceptibility index 0.28, 0.22, 0.47 the same genotype’s drought has caused a significant decrease in the number of tillers during the first season, second season and combined by 23.09, 26.30 and 24.67 respectively. The decrease rate due to drought increased in the number of spikes of plant 24.30, 26.16 and 25.20 respectively.
3- Spike length
Drought cause slight decrease in spike length compared to normal irrigation in the first season (11.38 and 12.65 cm), second season (10.75 and 12.67 cm) and combined means (10.06 and 12.66 cm).
The reduction in spike length due to drought in the first, second seasons and combined means were 10.08, 15.13 and 12.61, compared to normal irrigation condition, respectively. The longest spike was recorded for AIL112, AIL129, Sids12 under normal irrigation condition
4- Number of spikelets
The combined means indicated that AIL112, AIL129, AIL148, Sids12 were the best in number of spikelets under normal irrigation and AIL108, AIL129, AIL148 were the best in number of spikelets under drought.
5- Number spikes grain of genotypes
In the second and combined years, the genotype AIL129 was the most genotypic in drought resistance, but in the first year, 134 was the most tolerant to drought.
Drought has caused a significant reduction in the number of spikes grain of genotypes in the first, second seasons and combined 63.75, 29.67, 44.40, respectively.
B – Anatomical traits:that AIL120 occupies the first level among the genotypes in terms of the diameter in the case of control. As for AIL148, it occupies the first level under the influence of drought for Diameter of xylem while in Diameter of phloem. The genotype 148 was the largest, under the influence of control and 142 under the influence of drought
1-2- Vascular bundle diameter
Effect of drought on the diameter of vascular bundle, and this was evident in the descriptive analysis, as AIL103 genotypes were highest in terms of diameter, under the control, but under the effect of drought, they were AIL142 above.
1-3- Fibers thickness and stem diameter
Separate and combined analysis of variance for each experiment in the two seasons revealed highly significant differences among the evaluated wheat genotypes.
The best genotypes in fibers thickness AIL112 and stem diameter AIL148 A under effect of control but the tolerant AIL108, AIL112 in fibers thickness and sids12 under effect of drought.
2-Anatomical the leaf:
2-1- Leaf thickness, epidermal thickness, vascular bundle diameter
AIL142 was the best genotype in the thickness of the leaf under the influence of control, but under the influence of drought were sids12 best genotypes, and this was revealed through descriptive analysis.
2-2- Diameter of xylem, diameter of phloem
Under the influence of drought, the Sids 12 and 108 genotypes were the best of the ten genotypes. As for the control, AIL142 were the best.
Whereas, the analysis of variance showed significant differences in the first, second season and combined.
C – Physiological traits:
1- Total soluble protein
Variation in the effect of drought on protein content, and AIL129 and AIL142 genotypes can be considered the most resistant to drought, as it is the highest in protein content.
2- Potassium, calcium and magnesium content
A difference was found between the first and second years in the analysis of separate variation of the elements potassium, calcium and magnesium. As for the analysis of combined variance, the differences were significant.
As for descriptive analysis, it was explained that the effect of drought on these elements varies.
3- soluble sugars, total Fee amino acid, proline content
The effect of drought on some contents negative and on others in the positive
In the combined and pooled variance analysis, the differences were significant
As for descriptive analysis, the genotypes differed from one trait to another.
C – Yield traits:
1- 100-grain weight
The reductions in 100- grain weight due to drought in the first, second seasons and combined means were 11.15, 3.51 and 7.38 % compared to normal irrigation condition, respectively.
The combined means under normal irrigation indicated that AIL148 genotype had the heaviest grain weight, followed by AIL142, AIL108 and AIL129. Under drought, AIL1142 genotype had the heaviest grain weight, followed by AIL148, AIL134, AIL120, AIL103
Drought susceptibility index from the combined means indicated that AIL129, AIL120, AIL142, AIL112 , AIL108, AIL148 was tolerant their DS1 less than 1.0.
2- Grain yield per plant
The reductions in Grain yield per plant due to drought in the first, second seasons and combined means were 51.02, 84.08 and 66.77 % compared to normal irrigation condition, respectively.
The combined means under normal irrigation indicated that AIL148 genotype had the heaviest grain weight, followed by AIL129, AIL142 and AIL108. Under drought, AIL108 genotype had the heaviest grain weight, followed by AIL148, AIL103, Sids 12.
Drought susceptibility index from the combined means indicated that AIL148, AIL103, AIL108, AIL134 was tolerant their DS1 less than 1.0.
3- Grain yield genotypes
The reductions in grain yield genotypes due to drought in the first, second seasons and combined means were 77.29,76.44 and 76.78 % compared to normal irrigation condition, respectively.
The combined means under normal irrigation indicated that AIL148 genotype had the heaviest grain weight, followed by AIL129, AIL120, AIL108. Under drought, AIL148 genotype had the heaviest grain weight, followed by AIL112, Giza168, AIL134
Drought susceptibility index from the combined means indicated that AIL148, AIL112, AIL108, Giza168, Sids12 was tolerant their DS1 less than 1.0.