Abstract: The content of Na⁺,K⁺ and Plasma membrane H⁺-ATPase activity in leaves and roots of Achnatherumsplendens were determined in order to investigate the distribution of Na⁺,K⁺ and the plasma membrane H⁺-ATPase activity on Achnatherumsplendens under varying levels of NaCl and Na₂SO₄.Results show that with the concentration of NaCl and Na₂SO₄ increasing,the content of Na⁺ increased and K⁺ decreased,then K⁺/Na⁺ ratio decreased in roots and leaves of seedlings in Achnatherumsplendens.The PM H⁺-ATPase activity increased only in roots of Achnatherumsplendens.The content of Na⁺ in leaves was lower than that in roots,and the content of K⁺ in leaves was higher than that in roots under NaCl and Na₂SO₄ stress.The K⁺/Na⁺ ratio in leaves was more than 1 and higher than that in roots.The PM H⁺-ATPase activity in roots was higher than that in leaves.The TS_K,Na was higher under Na₂SO₄ stress than NaCl stress.The PM H⁺-ATPase activity in leaves and roots was higher under Na₂SO₄ stress than the same concentration of NaCl stress.Achnatherumsplendens was more tolerant to Na₂SO₄ stress than NaCl stress.

Key words: Salt tolerance, Achnatherumsplendens, Na⁺, K⁺, TS_K,Na, PM H⁺-ATPase

摘要： 以芨芨草(Achnatherumsplendens)种子萌发苗为试验材料,分别以不同浓度NaCl和Na₂SO₄进行胁迫,通过对芨芨草叶片和根系中Na⁺,K⁺含量以及质膜H⁺-ATPase活性进行测定,以探讨盐胁迫对芨芨草中Na⁺,K⁺分布以及质膜H⁺-ATPase活性的影响。结果表明:随着NaCl和Na₂SO₄浓度的增加,芨芨草根系和叶片的Na⁺含量增加,K⁺含量下降,K⁺/Na⁺比值下降,根系中质膜H⁺-ATPase活性增加;在NaCl和Na₂SO₄胁迫下,芨芨草叶片中Na⁺含量显著低于根系,K⁺含量显著高于根系,叶片的K⁺/Na⁺比值均大于1并明显高于根系,根系的质膜H⁺-ATPase活性显著高于叶片;与NaCl相比,Na₂SO₄胁迫下,芨芨草根系向叶片的离子选择性运输系数(TS_K,Na)较高,叶片和根系的质膜H⁺-ATPase活性明显高于相同浓度的NaCl胁迫组。与NaCl胁迫相比,芨芨草对Na₂SO₄胁迫的适应性更强。

关键词: 耐盐性, 芨芨草, Na⁺, K⁺, TS_K,Na, 质膜H⁺-ATPase