Seedlings of six Glycine max cultivars were used to compare Cl- with Na+ in stress effects on soybean seedlings under NaCl stress. Results showed that stress of NaCl on G. max seedlings was mainly caused by Cl- and not by Na+. After treatment with isoosmotic solutions of Cl- (without Na+) and Na+ (without Cl-) respectively, fresh weight and height of G. max seedlings growing in solution of Cl- were much more stressed than those in solution of Na+. And the roots and leaves electrolyte leakage were much more increased under stress of Cl- than those under stress of Na+. Salt tolerance of G. max seedlings was mainly contributed to Cl- withheld in roots of seedlings to decrease its content in leaves.
LUO Qing-yun, YU Bing-jun and LIU You-liang( College of Life Science , Nanjing Agricultural University , Key Laboratory of Crop Growth Regulation /National Center of Soybean Improvement, Ministry of Agriculture , Nanjing 210095 , P. R. China )
