ABSTRACT
Three Egyptian wheat (Shanadaweel 1, Giza168, and Masr 1)
varieties were evaluated under drought stress using different
concentrations of polyethylene glycol (PEG) (0, 1, 2, and 3 bars) and
investigate the effects of the application of ascorbic acid (0, 150, and 200
mg/L) in the alleviation of drought stress at the seedling stage. The
results revealed that drought stress caused a decrease in germination
percentage, growth parameters (shoot length and root length) and
photosynthetic pigments (chlorophyll A, chlorophyll B, and total
carotenoids) with increasing PEG concentrations in all wheat varieties.
Moreover, Catalase (CAT) activity increased in Giza168 with increasing
drought stress at 3 bar, whereas CAT activity increased in Masr 1 and a
nonsignificant increase in Shandaweel 1 at 1 bar and then decreased at 2
bar. Also, proline accumulation under drought stress in all wheat
varieties. On the other hand, pretreatment of seeds treated with ascorbic
acid (0, 150, 200 mg/l) enhanced all parameters studied under drought
stress. 200 mg/L of ASA is the most effective in mitigating the effects of
drought stress on the morphological and chemical characteristics of
wheat varieties at the seedling stage.