| In order to understand physiological and biochemical changes under drought stress, WL-323 alfalfa and Ao han alfalfa seedling were treated with different PEG concentrations of 10%,15% and 20% as slight, middle and serious stress levels of drought. After 10h,20h,30h, 40h and 50h of PEG treated, we analyzed the activities of SOD, POD, CAT and the contents of MDA, proline, sugar, and protein in leaves. The results were as follows:1, The activities of SOD and POD in both two alfalfal cultivars increased with drought level increased and time extend in 40 hours. After that, the activities of these two enzymes in Ao han were evidently declined while the activities in WL-323 still high.2, The activities of CAT and the content of MDA in both two alfalfal cultivars increased with drought level increased and time extend. The longer drought time and higher drought level, the bigger increase margin.3, With drought time extend and stress increasing, the contents of proline, sugar and protein in leaves of alfalfa increased by inducement. The accumulation of proline is the most visible. The function of proline is the most, sugar is the next and protein is the last.4, The abilities of penetration regulation and antioxidant enzymes regulation of WL-323 is better than Ao han while the ability of CAT regulation in Ao han is better than WL-323. |
