• 关键词：铜  硒  重金属  复合污染  小白菜  吸收  转运

• 基金项目：公益性行业(农业)科研专项(No.200903015-05);西北农林科技大学"创新团队建设计划"资助

• 胡斌
• 西北农林科技大学资源环境学院, 杨凌 712100

• 王丹
• 西北农林科技大学资源环境学院, 杨凌 712100

• 王松山
• 西北农林科技大学资源环境学院, 杨凌 712100

• 周萌
• 西北农林科技大学资源环境学院, 杨凌 712100

• 梁东丽
• 西北农林科技大学资源环境学院, 杨凌 712100

• 摘要：采用土培盆栽试验和室内分析相结合的方法,研究了不同含量铜、硒单一和复合污染对小白菜生长及金属铜、硒吸收和转运的影响.结果表明,适量的硒(2.5 mg · kg^-1)可以促进小白菜生长,表现为小白菜叶片叶绿素相对含量值(SPAD)、根长、地下和地上生物量的增加,但高含量硒(≥10.0 mg · kg^-1)却抑制小白菜的生长.外源铜单一污染或铜硒复合污染均能显著抑制小白菜生长,表现为小白菜叶片的SPAD值、 根长、茎长、地下和地上生物量均与外源铜含量呈显著负相关(p<0.01).复合污染处理中,相同铜含量水平下,小白菜地上部分铜含量随外源硒含量升高而增加,而地下部分铜含量则以Se含量10 mg · kg^-1处理最高;硒含量一定时,小白菜地上、地下部硒含量随外源铜含量升高呈现先升高后降低的趋势,以Cu含量为200 mg · kg^-1处理的硒含量最高.土壤中适量的硒(2.5 mg · kg^-1)与铜之间存在拮抗作用,而当外源硒含量高于10.0 mg · kg^-1时,硒与铜之间呈现协同毒害作用.硒能促进铜从小白菜根系向地上部的转运,而高含量铜胁迫则使得更多的硒滞留在小白菜地下部.

• Abstract：The effects of different concentrations of copper (Cu), selenium (Se) and their combination on the growth of pak choi and the uptake and transportation of Cu and Se in the plants were studied by means of pot experiments. The results showed that a proper amount of Se (≤2.5 mg · kg^-1) could promote the growth of pak choi, increasing the SPAD value (relative content of chlorophyll) of pak choi leaves, root and shoot lengths and root biomass. But high concentrations of Se(≥10.0 mg · kg^-1) could inhibit growth of pak choi. Exogenous Cu and Cu-Se combined inhibited the growth of pak choi significantly. The SPAD value, root length, stem length and biomass of shoots and roots had significant negative correlation with exogenous Cu concentration (p<0.01). In the combined Cu-Se treatment, with the same concentration of Cu, the content of Cu in shoots of pak choi increased with the concentration of Se in soil, while the Cu content in roots was highest with Se at 10 mg · kg^-1; when Se content was fixed, the biomass of shoots and roots of pak choi increased first and then decreased with increasing exogenous Cu concentration and the Se content was highest for the treatment with 200 mg · kg^-1 Cu. The proper content of Se (≤2.5mg · kg^-1) had antagonistic effects with Cu; but when the exogenous Se concentration was over 10 mg · kg^-1, Se exerted synergetic toxic effects with Cu. Selenium could promote transfer of copper from the root system of pak choi to the aerial part, while Cu could keep more selenium in the roots of pak choi.

• Key words：Cu  Se  heavy metal  combined pollution  pak choi  uptake  transport

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