Zn对大麦Cd、Cu毒性的影响及其联合毒性效应

鲍林林; 王学东; 华 珞

文章摘要

鲍林林,王学东,华珞.Zn对大麦Cd、Cu毒性的影响及其联合毒性效应[J].农业环境科学学报,2014,33(7):1273-1278.

Zn对大麦Cd、Cu毒性的影响及其联合毒性效应

Toxicity of Cadmium and Copper to Barley in Presence and Absence of Zinc

DOI：10.11654/jaes.2014.07.003

中文关键词: EC50 毒性单位（TU）联合毒性拮抗作用协同作用

英文关键词: EC50 toxic unit（TU） combined toxicity antagonism synergism

基金项目:

作者	单位
鲍林林	首都师范大学资源环境与旅游学院，北京 100048
王学东	首都师范大学资源环境与旅游学院，北京 100048
华珞	首都师范大学资源环境与旅游学院，北京 100048

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中文摘要:

通过模拟土壤溶液进行水培试验，研究了锌（Zn）对大麦（Hordeum Vulgare）镉（Cd）、铜（Cu）毒性的影响，以及Zn-Cd和Zn-Cu的联合毒性效应。结果表明：Zn、Cd和Cu单独作用于大麦时，EC50分别为78.01、2.98、0.64 μmol·L-1，Zn的毒性远远小于Cd和Cu。在Zn-Cd混合体系中，当Zn浓度低于5 μmol·L-1时，随着溶液中Zn浓度的增加，EC50（Cd）呈显著的线性增加，表明低浓度Zn对大麦Cd毒性具有抑制作用；利用毒性单位（TU）模型计算了Zn-Cd混合体系的TUmix值，结果显示TUmix≥1 TU，且TUmix随Zn浓度的升高而增加，表明Zn、Cd联合作用于大麦时主要表现为拮抗作用，且这种作用和混合体系中Zn的比例有关。在Zn-Cu混合体系中，随着Zn浓度的增加，大麦相对根长（RE）明显减小，EC50（Cu）逐渐降低，表明Zn增强了大麦Cu的毒性；Zn-Cu的TUmix均小于1 TU，Zn、Cu联合作用于大麦时表现为协同毒性作用。

英文摘要:

Metal toxicity to plants is different in single system from in multiple metal system. Here toxicities of individual Zn, Cd and Cu and Zn-Cd and Zn-Cu mixtures to barley（Hordeum Vulgare） were tested in nutrient solutions. Toxic unit（TU） model was used to evaluate the combined toxicity of mixture metals. EC50s（metal concentration at which root elongation is inhibited by 50%） were 78.01 μmol·L-1, 2.98 μmol·L-1 and 0.64 μmol·L-1 for Zn, Cd and Cu, respectively, indicating that Cu toxicity was much higher than Cd or Zn in single-metal system. In binary metal systems, Cd toxicity to barley was inhibited by Zn at 5 μmol·L-1, and the values of EC50（Cd） increased significantly. TUmix values of Zn-Cd were greater than 1 TU and increased with Zn concentrations, suggesting an antagonistic effect between Zn and Cd at low Zn concentrations. Such antagonism of Zn-Cd was correlated with Zn proportion in the mixture system. At higher concentrations（>5 μmol·L-1）, Zn exerted high toxicity to barley and increased the joint toxicity of Zn-Cd. Additions of Zn showed greater Cu toxicity to barley than Cu alone. EC50（Cu） values were higher in Zn-Cu mixture than in single-metal system and decreased dramatically with increasing Zn concentrations, showing synergistic toxicity of Zn-Cu. TUmix values of Zn-Cu mixture were less than 1 TU. These results suggest that Cd and Cu may have different toxicity mechanisms, and that more attention should be paid to combined heavy metal pollution.

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