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

Effects of PEG Simulated Drought Stress on Seedling Morphology and Physiological Characteristics of Different Drought-Resistance Maize Varieties

为探讨玉米(Zea mays L.)苗期对水分亏缺的响应机制,以抗旱性具有显著差异的2个玉米品种为材料,使用PEG-6000溶液模拟不同强度的干旱胁迫,对逆境中玉米苗期的形态及生理生化特性进行分析。结果表明:干旱胁迫后抗旱性强的成单30的株高、叶面积、根长及根重呈上升趋势,抗旱性弱的金玉306呈下降趋势;干旱胁迫使成单30的地上部干重、根重和干物重等生物产量增加,而金玉306的各生物产量逐渐下降;干旱胁迫导致玉米的丙二醛含量升高,细胞膜稳定性下降,成单30的变化幅度比金玉306小;干旱胁迫使玉米的叶绿素a/b比值及叶绿素含量下降,类胡萝卜素含量增加;成单30的可溶性糖及可溶性蛋白含量在干旱胁迫后变化不显著,而金玉306在后期才出现显著变化;干旱胁迫后,成单30与金玉306的脯氨酸含量均极显著增加;干旱胁迫使玉米的超氧化物歧化酶、过氧化物酶及过氧化氢酶活性提高。这些结果说明不同抗旱性玉米品种的抗旱机制存在一定差异。

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.