PEG模拟干旱胁迫对不同抗旱性玉米品种苗期形态与生理特性的影响

In order to explore the response mechanism of maize (Zea mays L.) to water deficit at seedling stage, this study used two maize varieties with significant differences in drought resistance as materials, and used PEG-6000 solution to simulate drought stress of different intensities, and the morphological, physiological and biochemical characteristics of maize seedlings were analyzed. The results showed that, after drought stress, the plant height, leaf area, root length, and root weight of Chengdan 30 with strong drought-resistance showed an increasing trend, while Jinyu 306 with weak drought-resistance showed a downward trend. Drought stress increased the shoot dry weight, root weight, and dry matter weight of Chengdan 30, while the yield of each organism of Jinyu 306 were gradually decreased. Drought stress led to an increase in malondialdehyde content and a decrease in cell membrane stability. Drought stress reduced the chlorophyll a/b ratio and chlorophyll content of maize, and increased carotenoid content. The soluble sugar and soluble protein content of Chengdan 30 did not change significantly after drought stress, but Jinyu 306 did not change significantly until the later period. Proline contents of Chengdan 30 and Jinyu 306 both increased significantly after drought stress. Drought stress increased the activities of superoxide dismutase, peroxidase and catalase in two maize varieties. These results indicate that the drought resistance mechanisms of maize with different drought-resistant are different.

Keywords： Maize ; Seedling stage ; Drought stress ; Response mechanism