Responses of mainphysiological and biochemical indexes of maize leaf to soil moisture at seedling stage | 玉米苗期叶片主要生理生化指标对土壤水分的响应

中国人. 摘　　要：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。

英语. The maize cultivars Longdan 57 was chosen as experimental material,in order to investigate the response rules of physiological and biochemical indexes,such as chlorophyll,malondialdehyde（MDA）,soluble sugar and praline（Pro）,to soil moisture,which was obtained by artificial water supply and natural consumption.The results indicated that the chlorophyll had threshold value to soil moisture（SWC）.The soil moisture range which could keep chlorophyll at relatively high level was 15.2%-25.6% for SWC and 51.6%-87.2% for relatively water content（RWC）.The SWC which had highest effectiveness on the content of chlorophyll was about 20.4%.The content of Pro and soluble sugar presented ascent trend on the whole with the increase of water stress,indicating that Pro and soluble sugar were the main osmotica in maize leaf.However,the incremental extent had discrepancy under different water conditions.The content of MDA presented a trend of first decrease and then increase,when the SWC was higher than 17%,the content of MDA changed inconspicuously,and when the SWC was less than 17%,the content of MDA presented a trend of steep rise with the increase of water stress,indicating that the lipid peroxidation of leaf plasma membrane also aggravated.