الفهرس | Only 14 pages are availabe for public view |
Abstract Studying the ability of 8 genotypes of bread wheat to tolerate or acclimatize drought stress. The obtained results could be summarized as follows: 1. Analysis of variance revealed that genotypes mean squares were highly significant for calli percentage, fresh weight , green points and plantlets percentages. 2. Calli percentage and weight were mainly controlled by genetic factors. However, embryo response and green points percentages as well as plantlets appeared to be highly affected by environmental conditions. 3. The studied genotypes varied in their response to drought stress and Misr 1 , Gemmeiza 7 and Gemmeiza 10 appeared to be more tolerant to drought stress whereas genotypes Sakha 8, Sakha 94 and Giza 168 were sensitive in this respect. However , the regeneration capacity are genotype dependent. 4. The most remarkable root anatomical features noticed in in vitro culture under drought stress for all selected genotypes are formation of internal air spaces within the cortical parenchymatous cells and well-developed exodermis. 5. There are some leaf anatomical evidences seemed to be responsible for drought tolerance of the selected wheat air spaces in the mesophyll tissue, remarkable increase in leaf or mesophyll thickness and remarkable increase in leaf hairiness. Conclusion: It could be concluded that, all measured parameters were greatly affected by drought stress. Moreover, wheat genotypes differed in their physiological response to water stress. Genotypes Misr 1 , Gemmeiza 7 and Gemmeiza 10 seemed to be more tolerant to drought stress . Tissue culture technique can be used safety for propagation of bread wheat to produce new lines representing materials needed further investigation. |