水分胁迫对小麦种子萌发及幼苗生长的影响

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。

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

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 H_2O_2,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 rate and chlorophyll content decreased,while H_2O_2 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.