基于干旱胁迫的沙地柠条生理生态响应

摘要 ：采用干旱胁迫处理沙地柠条幼苗，对其生长性状、叶绿素含量、脯氨酸、酶活性和丙二醛(MDA)进行了测定，结果表明：随着水分胁迫时间的延长和胁迫程度的加重，苗高的相对增长量和平均生长速率均呈现下降的趋势。柠条在轻度水分胁迫时相对生长速率为无胁迫的72.73%，而在严重胁迫下仅为对照的45.45%。在严重胁迫处理的后半期，柠条则逐渐表现出叶片枯黄、卷曲等受胁迫的症状；最后8.5%的柠条在胁迫的末期死亡。随着不同水分梯度的胁迫时间延长，严重胁迫和重度胁迫的叶绿素含量呈现先增加后降低的趋势，而无胁迫和轻度胁迫下叶绿素含量变化幅度不大，叶绿素a的含量初期表现为中度胁迫和严重胁迫的较高，后期严重胁迫叶绿素含量下降幅度最大，而叶绿素b在不同胁迫处理下均表现出先升高后下降的趋势。脯氨酸含量初期以轻度胁迫的较高，严重胁迫的脯氨酸含量较低，随着水分胁迫时间的延长严重胁迫处理脯氨酸含量明显上升，且在后期含量一直保持最高水平；严重胁迫后期POD含量明显高于其他处理措施，丙二醛的含量后期严重胁迫的最高，其次为轻度胁迫和中度胁迫，无胁迫的最低。

Based on drought stress Eco-physiological responses of the sandy land Caragana

Abstract: The growth traits, chlorophyll content, proline content,SOD activity and MDA content of sandyland Caragana korshinskii seedlings were measured after drought stress treatment. The results indicated that: with the prolongation and increasing of water stress, the relative growth and average growth rate showed decreasing trends. Under slight water stress the average growth rate was 72.73% of the control group while only 45.4% of it under severe stress, Leaves Showed brown, curly symptoms in the second half time of severe stress treatment, and finally 8.5% of the group died. As the time extended, the chlorophyll content under severe stress and moderate stress increased firstly and then decreased, however, those of slight stress and the control groups had minor changes, the content of Chlorophyll a appeared higher under moderate stress and severe stress in the primary stage, but it dropped the most violently in a later period under severe stress. the Chlorophyll b contents under the four levels all rose at first and got lower then. The proline content present higher under slight stress and lower under severe stress, nevertheless, under severe stress it rose significantly as the time passed and even kept the highest level in the later part, when POD content was also higher obviously than the other treatments. In cast of the MDA content, in the later stage, it got the maximum under severe stress, the followings were slight stress, Moderate stress and the control group.