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以玉米品种龙单57为试验材料,通过人为供水和自然耗水相结合的方法获得多级土壤水分梯度,探究其生理生化指标(叶绿素、脯氨酸、可溶性糖及丙二醛)对土壤水分的响应规律。结果表明,玉米叶绿素含量对土壤水分(SWC)的变化具有阈值响应,维持玉米叶片叶绿素含量较高水平的SWC范围在15.2%～25.6%,相对含水量(RWC)为51.6%～87.2%,SWC在20.4%左右是对玉米叶片叶绿素含量有效性最高的土壤水分。随着水分胁迫程度的增加,脯氨酸累积量和可溶性糖含量总体上均呈现上升趋势,表明脯氨酸和可溶性糖为玉米的主要渗透调节物质,但在不同的水分条件下,增加的幅度有所差异。丙二醛含量随着土壤含水量的减少呈现先减少后增多的趋势,SWC>17%时丙二醛的含量变化不明显,SWC<17%时丙二醛的含量随着水分胁迫程度的加重急剧上升,叶片质膜膜脂过氧化作用也随之加剧。
A multi-grade soil moisture gradient was obtained from a combination of man-made water supply and natural water consumption by using maize variety Longdan 57 as test material, and its physiological and biochemical indexes (chlorophyll, proline, soluble sugar and malondialdehyde) The response law. The results showed that the chlorophyll content of corn had a threshold response to the change of soil water content (SWC). The range of SWC with high chlorophyll content was 15.2% -25.6% and the relative water content (RWC) was 51.6% -87.2% About 20.4% is the most effective soil moisture to the chlorophyll content of maize leaves. With the increase of water stress, proline accumulation and soluble sugar content all showed an upward trend, indicating that proline and soluble sugar were the main osmotic adjustment substances for maize, but under different water conditions, the increasing range Some differences. With the reduction of soil water content, the content of malondialdehyde firstly decreased and then increased. The content of malondialdehyde did not change obviously when SWC> 17%, and the content of malondialdehyde increased with the degree of water stress at SWC <17% Sharp rise, leaf plasma membrane lipid peroxidation also will be aggravated.