Effect of Adaptive Capacity of Alfalfa Seedlings to NaHCO_3 Stress

In order to select basic-resistant alfalfa germplasms,4 alfalfa varieties were sown under conditions of differet NaHCO3 concentrations.chlorophyll content,malondialdehyde content (MDA) and proline content of leaves were measured and the data were subjected to integrated weighting analysed.The results indicated that every physiological and biochemical index changed regularly.Content of proline and MDA were increasing with NaHCO3 increased.Chlorophyll content all increased but Caoyuan No.1 when NaHCO3 concentration increased.All seedlings died at the seventh day when NaHCO3 concentration reached up to 200mmol/L.The sequence of resistance to NaHCO3 stress of four alfalfa variety as follow:803Caoyuan No.1806Zhaodong.