Na2SO4胁迫对四种抗盐性不同牧草膜脂过氧化和活性氧清除系统的影响

 经过1%和2%的Na2SO4胁迫后，草原绢蒿，圆叶蒿，苇状羊茅和鸭茅4种牧草的膜脂过氧化程度和质膜的透性都增加，但抗盐性较强的草原绢蒿和苇状羊茅的膜脂过氧化程度及质膜透性分别低于同科中抗盐性较差的圆叶蒿和鸭茅。随着Na2SO4胁迫浓度的增加，两种禾本科牧草的超氧化物歧化酶(SOD)及过氧化氢酶(CAT)的活性逐渐升高，两种菊科牧草的SOD及CAT的活性却逐渐下降，但禾本科中抗盐性较强的苇状羊茅的SOD及CAT活性的增长率要大于抗盐性较差的鸭茅，菊科中抗盐性较强的草原绢蒿的SOD及CAT活性的下降率要小于抗盐性较差的圆叶蒿。在Na2SO4胁迫下，两种抗盐性较强牧草的类胡萝卜素的相对含量要分别高于同科中抗盐性较差的牧草。

EFECT OF Na_2SO_4 STRESS ON MEMBRANE-LIPID PEROXIDATION AND SCAVENGING SYSTEM OF ACTIVATED OXYGEN IN FOUR GRASSES WITH DIFFERENT SALT RESISTANCE

Exposed to high concentrations of Na_2SO_4(1%and 2%),the permeability of plasma membrane and membrane-lipid peoxidation of Seriphidium schrenki-anum, Artemisia ratifolia,Festuca arundinacea and Dactylis glomerata were increased.But the increases in the permeability of plasma membrane and the membrane-lipid peroxidation were more prominent in salt-resistant species,Seriphidium schrenkianum and Festuca arundinacea,than the salt-sensitive spe-cies, Artemisia ratifolia and Dactylis glomerata. The activities of the supero-xide dismutase(SOD)and catalase(CAT)in the graminaceous family (F.arundinacea and D. glomerata) increased with increasing concentration of Na_2SO_4,while those in the composite family(S. schrenkianum and A. ratifo-lia) decreased.In the graminaceous family, the rate of increase of SOD and CAT activities in the salt-resistant grass(F. arundinacea)was higher than that in the salt-sensitive grass(D. glomerata),while in the composite family,the rate of decrease of SOD and CAT activities was lower in the salt-resistant grass(S.schrenkianum) than that in the salt-sensitive species(A,ratifolia).Within the same family, the relative contents of carotene in the salt-resistant grasses were higher than those in the salt-sensitive grasses.