水分胁迫对小麦种子萌发及幼苗生长的影响

Effect of Water Stress on Seed Germination and Seedling Growth of Wheat

采用人工控水的方法,考察土壤含水量分别为9%、12%1、5%、18%2、1%及24%时小麦种子萌发及幼苗生长方面的相关指标。结果表明,随土壤含水量的下降,小麦萌发率、苗高及叶绿素含量呈下降趋势,小麦幼苗H2O2与MDA含量呈上升趋势,且水分胁迫越严重趋势越明显。幼苗自由基清除相关酶活性的变化各不相同,SOD与POD活性在水分胁迫初期呈上升趋势,后期呈下降趋势;CAT活性在水分胁迫初期变化不大,后期则呈下降趋势。说明水分胁迫能加剧小麦幼苗膜脂过氧化从而引起膜的损伤,且膜脂过氧化的程度随水分胁迫的加大而加深;幼苗自由基清除相关酶活性在胁迫初期会上升以抵抗水分胁迫,后期则下降,且不同的酶在抗水分胁迫中的作用不同。

In this article, the influence of water-stress on germination and growth of seedlings in wheat （Triticum aestivum L. ） were studied. Wheat were planted in plastic pots in a greenhouse under different water content of soil, including 9% ,-12%, 15%, 18% ,21% and 24%. Germination rate and content of H2O2,MDA and chlorophyll were measured. Also, enzymatic antioxidants such as SOD, POD, CAT which clean AOS,existed in plant cells, were studied. The results showed that germination rote and chlorophyll content decreased, while H202 and MDA content increased with the increasing of water content of soil. SOD and POD activities raised and CAT activities had no significantly change under slightly drought-stress,but it was decreased under severe stress .These results suggested that the system of defense enzymes might play a key role by balancing all of the responding enzymes under drought condition in plants.