摘要
在科尔沁沙地选择处于不同演替阶段的几种优势植物 ,通过测定干旱高温处理下植物形态变化和生理反应 ,分析讨论了植物生理抗逆性差异及其与植物演替的关系。结果表明 ,固定沙地上的狗尾草、白草在胁迫过程中叶片萎蔫 ,复水后恢复生长 ,其保护酶对胁迫反应快 ,可溶性糖、游离脯氨酸含量增加 ,是一真正的生理抗逆植物。半固定沙地上的差巴嘎蒿在胁迫过程中叶发黄 ,但在复水后能恢复生长 ,这与其在胁迫过程中游离脯氨酸含量增加 ,维持叶渗透压减少水分过度丧失有关 ,半固定沙地芦苇在胁迫过程中叶干枯死亡 ,原因是其细胞保护酶反应迟钝 ,积累的氧自由基引起膜脂过氧化作用伤害了膜系统。在干旱高温胁迫下 ,流动沙地上的沙米和欧亚旋覆花植株迅速脱水死亡 ,而细胞内膜脂过氧化作用强烈引起细胞膜严重受损是其死亡的主要原因。这说明 ,在生境从固定沙地向流动沙地演变过程中 ,不同植物抗逆性的差异在植被演替序列中起重要作用 ,植物演替的生理机制是从较为抗旱到较为不抗旱 ,从生理抗旱向躲避干旱发展。
By selecting some superior plants in different succession stages in Horqin Sandland,China,this paper analyzes the difference of their physiological reversal-resistance and their relationship with succession through measuring their shape change and physiological reaction under high-temperature treatment.The results show that the leaves of Sataria viridis and Pennisetum centrasiaticum are wilting under stress conditions but can regrow when water is supplied,the protective enzyme is quick in reacting to stress conditions,the content of soluble carbohydrate and free proline increases, and these two kinds of plants are the genuine reversal-resistant plants. The leaves of Artemisia halondendron growing in semi-fixed sandland become yellow under stress conditions but can regrow when water is supplied,which is related to the increase of the content of free proline and the over loss of moisture due to osmoregulation.Phragmites australis withers and dies under stress conditions because the protective enzyme of cells is slow in reacting and the membrane systems are injured by membrane peroxidation caused by the accumulated free radicals of oxygen. Under the stress of aridity and high temperature,Agriophyllum squarrosum and Convolvulus chinensis dehydrate and die rapidly due to the serious injury of cell membrane,which is caused peroxidation of the internal membrane of cells.These reveal that the differance of reversal-resistance of different plants plays an important role in succession of plants in the habitat evolving from fixed sandland to mobile sandland,and the physiological mechanism of succession of plants develops from drought-resistance to drought-irresistance.
出处
《干旱区研究》
CSCD
2001年第3期13-19,共7页
Arid Zone Research
基金
国家 973项目G2 0 0 0 0 4870 4课题<沙漠化的生物过程与植被恢复重建机理>
973项目G19990 434 0 4课题<人类活动的生态效益及其对干旱化的影响>的资助
