Physiological responses of Vicia faba L. seedlings under NaCl and NaHCO_3 stress

Vicia faba L.seedlings were treated with different concentrations of NaCl and NaHCO3 for 7 days,and the fresh weight,malondialdehyde(MDA) content,free proline content,and the activities of antioxidant en-zymes were determined.The results were as follows.With the increase of NaCl and NaHCO3 concentrations,fresh weight of Vicia faba L.seedlings first increased significantly and then declined,MDA and free proline contents increased significantly,and the increase extent under NaCl stress was lower than under NaHCO3.The activity of superoxide dismutase(SOD) first increased significantly and then declined.The activity of peroxidase(POD) increased significantly under NaCl stress,and first rose and then decreased significantly under NaHCO3 stress.The activity of catalase(CAT) increased significantly.In conclusion,Vicia faba L.could resist salt and alkali stress to a certain degree.The responses of Vicia faba L.to alkali stress were more obvious than that to salt stress on average.