Effects of Arbuscular Mycorrhizal Fungi on Osmoregulation Substance Contents and Antioxidant Enzyme Activities of Cucumber Seedlings under Salt Stress

The effects of arbuscular mycorrhizal fungi(AMF) on osmoregulation substance contents and antioxidant enzyme activities in cucumber varieties 'Jinchun No.2' under salt-stress were studied in greenhouse.The results showed that:(1)soluble protein,soluble sugar,proline and malondialdehyde(MDA) contents,superoxide anion(O-·2) production rates,superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) activities in cucumber seedlings under 0.6% NaCl salt-treatment were higher than that of control;(2)Under salt stress,after AMF-inoculation,soluble protein,soluble sugar and proline contents,SOD,POD and CAT activities further increased,while MDA content and O-·2 production rate decreased;under non-salt stress,AMF-inoculation significantly increased soluble protein,soluble sugar and proline contents,SOD,POD and CAT activities,while MDA content and O-·2 production rate were as same as control in cucumber seedlings.AMF could enhance the seedlings osmotic adjustment mechanism of salt tolerance,raise the activities of antioxidant enzymes,decrease the membrane lipid peroxidation.So the damage of salt stress on the plant would be alleviated and the adaptability of cucumber seedlings to salt environments would be improved.