重金属Cu2+·Zn2+胁迫对紫花苜蓿种子萌发及生长的影响

目的]探索Cu^2＋和Zn^2＋胁迫对紫花苜蓿种子萌发、根长及植株生长的影响。方法]重金属胁迫分别设置9个浓度梯度：Cu^2＋为0、10、25、50、80、100、200、300和400mg／L；Zn^2＋为0、50、100、150、200、300、400、500、600mg／L，利用组织培养方法，研究Cu^2＋和Zn^2＋胁迫对紫花苜蓿种子萌发及生长的影响。结果]低浓度Cu^2＋≤25mg／L、Zn^2＋≤100mg/L对紫花苜蓿的萌发率、根长和株高生长具有促进作用，并且在Cu^2＋为10mg／L、Zn^2＋为100mg／L时根长和植株生长达到最佳。随着Cu^2＋、Zn^2＋浓度的增加，Cu^2＋浓度≥50mg／L，Zn^2＋≥150mg／L时对紫花苜蓿萌发率、根系和植株生长抑制作用逐渐加大，高浓度时Zn^2＋浓度为600mg／L、Cu^2＋浓度为400mg／L时，抑制作用最明显。结论]不同Zn^2＋和Cu^2＋浓度对紫花苜蓿种子的萌发率、根长和植株生长有不同影响作用。

Effect of Heavy Metal Cu2+and Zn2+ Stress on Seed Germination and Plant Growth of Common Alfalfa

Objective] The study aimed to explore the effects of Cu2+and Zn2+ stress on the seed germination,root length and plant growth of common alfalfa.Method] The heavy metal stress was set up by 9 concn.grades for Cu2+ as 0,10,25,50,80,100,200,300 and 400 mg/L and Zn2+as 0,50,100,150,200,300,400,500,600 mg/L and the effect of Cu2+and Zn2+ stress on the seed germination and plant growth of common alfalfa were studied by using the tissue culture method.Result] The low concn.of Cu2+ at ≤ 25 mg/L and Zn2+at ≤100 mg/L had some improvement on the seed germination,root length and plant growth of common alfalfa and when Cu2+was 10 mg/ L and Zn2+was 100 mg/L the root length and plant growth of common alfalfa were optimum.Along with the increase of Cu2+and Zn2+ concn.,Cu2+at ≥ 50 mg/L and Zn2+at ≥150 mg/L showed a gradual-increasing inhibition on the seed germination,root length and plant growth of common alfalfa and the high concn.of Zn2+at 600 mg/L and Cu2+at 400 mg/L had most obvious inhibition.Conclusion] Cu2+and Zn2+ with different concn.had different effects on the seed germination,root length and plant growth of common alfalfa.