Effects of Exogenous Selenium on Physiological Characteristics of Mung Bean Seedling Under Cd Stress

The effects of additional Se4+(0.8,1.6,2.4,3.2,4.0 mg/L) on the ultraweak photon,chlorophyll content,soluble protein content of mung bean seedlings under the stress of Cd2+(10,20 mg/L) were studied by hydroponic experiment.The results indicated that ultraweak photon increased firstly then decreased,again increased along with the increase of stress time.The Se4+ of 0.8,1.6 mg/L could increase ultraweak photon of mung bean seedlings under the stress of two kinds concentration Cd2+ while the concentration of Se4+ with 1.6 mg/L was the best.Under stress of Cd2+ with 10,20 mg/L,chlorophyll content and soluble protein content of leaves in mung bean seedling increased firstly and then decreased with the increasing of Se4+ concentrations.When Se4+ concentration was less than 4.0 mg/L,chlorophyll content and soluble protein content were higher than that under single stress with Cd2+,and the value of chlorophyll content and soluble protein content in the treatment with 1.6 mg/L Se4+ were the highest.Under the stress of 10 mg/L Cd2+,the proline content of leaves in mung bean seedlings increased firstly and then decreased with the increasing of Se4+ concentrations.When Se4+ concentration was less than 4.0 mg/L,proline content was higher than that of single stress with Cd2+ and proline content was the highest with 1.6 mg/L Se4+.Proline content decreased gradually with the increasing of Se4+ concentrations under the stress of 20 mg/L Cd2+.When Se4+ concentration was less than 2.4 mg/L,proline content was higher than that of single stress with Cd2+ and proline content was the highest under the treatment with 0.8 mg/L Se4+.The research showed that when the Se4+ concentration was less than 2.4 mg/L,there was alleviation effect on mung bean seedlings under the stress of Cd2+ with 10,20 mg/L,and the treatment with 1.6 mg/L Se4+ had the best effect.