Effect of Drought on Root Physiological and Biochemical Characters of Different Maize Cultivars during Seedling Stage WANG Si-si

23 maize varieties with different drought resistance were used as materials and 20%PEG solution was used to induce drought stress in this experiment.The changes of root physiological and biochemical characters and their relationship with drought resistance were studied under drought stress.The results showed that the drought stress during seedling stage could increase the ratio of root to shoot and root activity.The increasing amplitude of drought-tolerant maize hybrids was the largest.Under drought condition,the activity of superoxide dismutase(SOD) increased and the increasing extent of droughttolerant hybrids was the highest.The MDA content in roots of different maize hybrids increased and the lowest gradient of MDA content changes in the drought-tolerant maize varieties.The drought-tolerant maize hybrids had advantage under drought stress during seedling stage,because of the stronger root activity and the ability against active oxygen in root system.