松嫩平原羊草和虎尾草耐盐碱生理生态特性的比较研究

Comparative Study on the Saline-alkali Tolerance Physiological and Ecological Character of Leymus Chinensis and Chloris Virgata in Songnen Plain

实验采用野外不同盐碱化程度草地(pH值分别为7.56、8.18、8.3、9.2、9.81和总盐量分别为0.05%、0.12%、0.15%、0.24%、0.32%)的主要禾本科优势植物羊草和虎尾草为野外实验材料,与室内模拟生境(不同梯度混合盐碱,pH值分别为7、7.7、8.4、9.1、9.8)相结合的方法,对羊草和虎尾草在盐碱胁迫下生理、生态指标的动态变化及响应情况进行研究,实验结果如下:随着盐碱胁迫强度的增加,羊草和虎尾草叶片叶绿素含量降低,叶片游离脯氨酸含量升高;牧草叶片叶绿素含量和游离脯氨酸含量与其耐盐碱性显著正相关;高盐碱胁迫抑制了羊草和虎尾草的生长,草群高度和密度均有明显的降低趋势,而较低盐碱(pH8.18,总盐量0.12%)促进了羊草的生长,羊草高度和密度略有增加;羊草和虎尾草生长同期,高度差、密度差随盐碱胁迫的增强而逐渐变小,这些表明虎尾草比羊草更耐盐碱。

In order to further screen salt tolerance gene,breed high saline-alkali tolerance grass and improve Grassland saline-alkalized Songnen Plain,the Dynamic Change and response of physical,ecological indices of Leymus chinensis and Chloris Virgata under salt and alkaline stress was studied by using the method of combined major grass dominant plants which were Leymus chinensis and Chloris Virgata respectively and existed as the wild grasses of different salinity levels（pH was 7.56、8.18、8.3、9.2、9.81 respectively and the total salt amount was 0.05%、0.12%、0.15%、0.24%、0.32% respectively.） with indoor simulated habitat（Different gradient salt mixture at pH： 7、7.7、8.4、9.1、9.8 respectively）.The results were as follows：With the increase of Saline-alkali stress intensity,the free proline content was increased in the leaves of Leymus chinensis and Chloris Virgata,but leaf chlorophyll content was decreased.Both Leaf chlorophyll content and the free proline content had positive correlation with saline-alkali tolerance;High saline-alkali stress could inhibit growth of Leymus chinensis and Chloris Virgata and the height of grass group,density had apparently decreased tendency,but lower saline-alkali stress（pH 8.18,the total salt amount of 0.12%） could promote growth of Leymus chinensis and the height of Leymus chinensis,density were slightly increased.These show that Chloris Virgata was more saline than Leymus chinensis.