盐胁迫对NHC牧草叶片保护酶系统，MDA含量及膜透性的影响

以Hoagland培养液培养NHC牧草（NewHy Crested Wheatgrass），3周后对幼苗进行NaCl和土壤盐胁迫处理。结果表明在300mmol／L土壤盐处理条件下，NHC牧草各生理指标极显著变化，7d后死亡。其他各处理条件下，超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、过氧化氢酶（CAT）活性、丙二醛（MDA）含量及膜透性均随处理液浓度的增加而极显著增加。盐胁迫下，NHC牧草通过增加SOD、POD、CAT酶活性提高耐盐性，降低MDA含量及膜透性增加带来的盐伤害。NHC牧草耐盐临界浓度分别为土壤盐200mmol／L，NaCl浓度300mmol／L。同样浓度条件下，土壤盐溶液对NHC牧草的伤害比NaCl溶液更大。

Effects of salt stress on protective enzyme system, MDA content and membrane permeability of NHC foliar

Aiming at improving the soline-alkali soil containing mainly NaCl in the area of Yingkou City,Liaoning Province,partial mechanisms of salt tolerance of NHC(new hybrid crested wheatgrass)were studed.Methods:NHC seedlings were cultured with Hoagland nutrient solution,and treated with soil salt solution and NaCl solution after 3 weeks.Results show that all of physiological indexes changed evidently and died after 7 days under 300 mmol/L of soil salt solution while SOD,POD,CAT enzyme activity and the content of MDA and membrane permeability increased evidently with the increasing of salt contents in other treatment.Conclusion:NHC decreases salt-harm that originning from the increasing of MDA and membrane permeability through increasing the enzyme activity of SOD,POD and CAT.The critical halo-tolerant concentration of NHC is 300 mmol/L NaCl salt solution or 200 mmol/L of soil salt solution.The harm of soil salt solution on NHC is larger than NaCl solution under the same concentration treatment.