4种抗盐性不同牧草对Na_2SO_4胁迫的反应

研究了４种抗盐性不同牧草对Ｎａ２ＳＯ４胁迫的反应，经过１％和２％Ｎａ２ＳＯ４胁迫后，草原绢蒿、贺叶蒿、苇状羊茅和鸡脚草的叶水势、叶片相对含水量及可溶性糖的含量都随Ｎａ２ＳＯ４浓度增加而逐渐下降；脯氨酸和游离氨基酸含量都随Ｎａ２ＳＯ４浓度增加而逐渐上升。抗盐性较强的草原绍蒿和苇状羊茅的叶水势和叶片相对含水量的下降率要分别低于同科中抗盐性较差的圆叶蒿和鸡脚草；可溶性糖的下降率却大于圆叶蒿和鸡脚草；草原绢蒿和苇状羊茅的脯氨酸和游离氨氨基酸的增长率要分别大于圆叶蒿和鸡脚草。在ｌ％Ｎ８２ＳＯＩ胁迫下，两种禾本科牧草的叶绿素含量明显增加，但经２％Ｎａ＿２ＳＯ＿４胁迫后又开始下降，苇状羊茅的叶绿素含量始终高于鸡脚草。两种菊科牧草叶绿素含量随着Ｎａ＿２ＳＯ＿４浓度的增加而逐渐下降，其中，草原绢蒿叶绿素的下降率要低于圆叶蒿的下降率。

Responses in Four Herbages Withe Different Salt Resistance to Na_2SO_4 Stress

The responses in four herbages with different salt resistance to Na2SO4 stress were studied. With the increase of stress concentration of Na2SO4 the leaf water potential,relative water content of leaf and the content of soluble sugar of Seriphidinm schrenkiaum,A rtemisia ratifolia, Festuca arundinacea and D acty lis g lomerata decreased,while the content of free proline and,free amino acid increased. The decrease rate of leaf water potential and relative water content of leaf in salt resistant herbages Seriphidium schrenkianum and Festuca arundinacea was lower than that in salt sensitive hebages Artemisia ratifolia and Dactylis glomerata respectively;while the decrease rate of soluble sugar in salt resistant herbages was higher than that in salt sensitant herbages respectively;the increase rate of free proline and free amino acid in salt resistant herbages was higher than that in salt sensitive herbage respectively. The content of chlorophyll in graass family increased after the stress of 1% Na2SO4, but then decreased after the stress of 2% Na2SO4; with the increase of stress concentration of Na2SO4 the content of chlorophyll in composite familly dcreased gradually.