Effects of NaCl Stress on Physiological Characters of Soybean Hybrids from Glycine max×Glycine soja

Seedlings of fifteen stable soybean lines from Glycine max×Glycine soja,as well as male parent YDD(Glycine soja)and local control cultivar KYDD(Glycine max),were exposed to 0,50,100,150 and 200 mmol·L-1 NaCl,and protective enzyme activity,content of Malondialdehyde(MDA)and osmotic regulation substances were determined to screen soybean materials with higher salt tolerance.With the increment of NaCl concentration,MDA content significantly increased,activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)decreased with varied degree,soluble protein(SP)declined,free proline(Pro)slightly increased,soluble sugar(SS)content was lower and remained stable.Under different concentrations of NaCl,SOD,POD and CAT activities of ZS,2 and 15-1 were obviously higher than YDD and KYDD,whlie MDA,Pro and SS were lower,and SP were higher thanYDD and KYDD for 15-1.Hence,15-1 had best salt tolerance from tested soybean lines.