外源硒对镉胁迫下绿豆幼苗生理特性的影响

采用水培试验方法研究不同浓度Se4+(0.8,1.6,2.4,3.2,4.0mg/L)对Cd2+(10,20mg/L)胁迫下绿豆幼苗超微弱发光及幼苗叶片中叶绿素、可溶性蛋白质和脯氨酸的影响。结果表明,随着胁迫时间延长,不同浓度Se4+对2种浓度Cd2+胁迫下绿豆幼苗的超微弱发光强度均呈现先升高后降低再升高的趋势,0.8,1.6mg/L的Se4+对2种浓度Cd2+胁迫下绿豆幼苗的超微弱发光强度均有促进作用,但是1.6mg/L浓度的Se4+对2种浓度Cd2+的缓解作用最佳。随着Se4+浓度的增加,2种浓度Cd2+胁迫下,绿豆幼苗叶片中叶绿素含量和可溶性蛋白质含量均呈现出先增加又减小的趋势,当Se4+浓度低于4.0mg/L时,叶绿素含量和可溶性蛋白质含量均高于单一Cd2+胁迫下叶绿素含量和可溶性蛋白质含量,且在Se4+浓度为1.6mg/L时达到最大。在10mg/L Cd2+胁迫下,随着Se4+浓度的增加,绿豆幼苗叶片中的脯氨酸含量先增加后减小,当Se4+浓度低于4.0mg/L时,脯氨酸含量高于单一Cd2+胁迫下脯氨酸含量,且Se4+浓度为1.6mg/L时脯氨酸含量达到最大;在20mg/L Cd2+胁迫下,随着Se4+浓度的增加,绿豆幼苗叶片中的脯氨酸含量逐渐降低,当Se4+浓度低于2.4mg/L时,脯氨酸含量高于单一Cd2+胁迫下脯氨酸含量,且Se4+的浓度为0.8mg/L时脯氨酸含量最大。研究表明在试验浓度范围内,Se4+浓度低于2.4mg/L时,对10,20mg/L Cd2+胁迫下的绿豆幼苗的毒害均有缓解作用,且浓度为1.6mg/L时缓解作用最佳。

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.