拔节期干旱对不同玉米品种叶片生理特性的影响及抗旱性分析

为筛选玉米抗旱品种及探究抗旱机制。本研究以目前主推的6个玉米品种为试验材料,在拔节期进行水分中度胁迫试验,分析干旱胁迫下6个玉米品种的丙二醛含量、叶绿素含量、可溶性蛋白含量、脯氨酸含量、超氧化物歧化酶和过氧化物酶活性。发现6个玉米品种在干旱胁迫下表现出了不同的生理响应机制,6个玉米品种叶片的丙二醛含量、叶绿素含量均不同幅度的显著下降,脯氨酸含量、可溶性蛋白含量、超氧化物歧化酶和过氧化物酶活性均不同程度的显著升高。干旱胁迫下,尤其‘郑单988’和‘郑单6386’的MDA含量升高幅度较低,叶绿素含量下降幅度较小,抗氧化酶活性升高幅度较大,可溶性蛋白和脯氨酸含量较高;相反‘郑单958’相对于‘郑单6386’和‘郑单988’,生理生化层面表现出较弱的抗旱性。结果表明拔节期‘郑单988’和‘郑单6386’的抗旱性较‘郑单958’强。本研究结果对揭示玉米耐旱机理有一定的重要意义,并可以为玉米耐旱种质筛选、改良和分子育种提供有效的指导和参考。

Drought Stress at Jointing Stage: Effects on Physiological Characteristics and Drought Resistance of Maize Varieties

The aims are to screen drought-resistant varieties and explore drought-resistant mechanisms of maize. Six maize varieties were selected as materials, and moderate water stress was carried out at jointing stage. The malondialdehyde content, chlorophyll content, soluble protein content and strontium ammonia of the six maize varieties were analyzed under drought stress. It was found that the six maize varieties showed different physiological response mechanisms under drought stress. The malondialdehyde content and chlorophyll content of the leaves of the six maize varieties decreased significantly, and the proline content, soluble protein content, superoxide dismutase and peroxidase activities increased significantly. Under drought stress, the increase of MDA content in ‘Zhengdan 988’ and ‘Zhengdan 6386’ was relatively low, the decrease of chlorophyll content was smaller, the activity of antioxidant enzyme increased, and the content of soluble protein and proline was higher. On the contrary, ‘Zhengdan958’ showed weaker drought resistance on the physiological and biochemical level than ‘Zhengdan 6386’ and ‘Zhengdan 988’. The results showed that the drought resistance of ‘Zhengdan 988’ and ‘Zhengdan 6386’ in jointing stage was stronger than that of ‘Zhengdan958’. The results have certain significance for revealing the drought tolerance mechanism of maize, and can provide guidance and reference for screening, improving and molecular breeding of drought-tolerant germplasm in maize.