基于干旱胁迫的沙地柠条生理生态响应

Rresponse of Eco-physiology of Caragana Korshinskii Kom to Water Stress in Desert Land

通过研究柠条对干旱胁迫的生理生态响应,从而为干旱风沙区柠条的抗旱机理及造林技术提供科学依据。采用正常水分处理(Control,CK)、轻度水分胁迫(Light stress,T3)、中度水分胁迫(Mediumstress,T2)和重度水分胁迫(Severe stress,T1)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。

In order to supply the scientific foundation in process of afforestation in desert zone, in this paper, the response of eco-physiology of Caragana Korshinskii Kom to drought stress was learned. The growth status, chlorophyll content, Pro, POD content, and MDA of the seedling of Caragana Korshinskii Kom were measured under 4 water levels include Control （CK）, Light water stress （T3）, Medium water stress （T2）, Severe water stress （T1）.The results indicated that the relative growth and average growth rate of the seedling decreasing with the drought time and water stress level~ Compared with CK, the seedling relative growth rates under light water stress was 72.73%, and the seedling relative growth rates under severe water stress was 72.73%. Under severe water stress, the seedling leaves showed brown, curly symptoms in later period, and 8.5% of the seedling died at last. The seedling chlorophyll content under medium water stress and severe water stress showed a trend in- creasing in early and decreasing in later period, and and light water stress showed mild changes water stress was higher, in later period the seedling chlorophyll content under the treatment of CK ; The chlorophyll A content under medium water stress and severe chlorophyll A content was decreased obviously; The chlorophyll B content showed a trend increasing in early and decreasing in later period under different water stress. The Pro content under light water stress was higher than medium water stress in early stage; The Pro content under se- vere water stress increasing with the time of water stress, and keep in a higher level at last stage. The POD con- tent under severe water stress was higher than other treatments. The MDA content under severe water stress was highest, and the followings were slight water stress and medium water stress, CK lowest.