| With an experiment,the effect of Cd2+ for 0～5 mg/L on physiological characteristics of alfalfa varieties Algonquin and Xinjiangdaye was studied.The results show that the Cd2+ treatment at lower concentration and at higher concentration can decrease the germination rates and the germination vigor,the middle Cd2+ treatment can increase the germination rates and the germination vigor.It is shown that "decreasing-increasing-decreasing".With the Cd2+ treatment increasing,the germination index and vitality index were decreasing,hypocotyl length,root length,shoot length,fresh weight on and under ground were decreasing.With the Cd2+ treatment increasing,proline contents,permeability of plasmalemma and MDA contents were increasing.With the same Cd2+ treatment,proline contents: Xinjiangdaye is higher than Algonquin;permeability of plasmalemma:Xinjiangdaye is lower than Algonquin;MDA contents:Xinjiangdaye is lower than Algonquin.The experiment may suggest that Algonquin is stronger to resist against Cd2+ stress than Xinjiangdaye. |