【摘要】 比较和分析了锌镉复合处理对东南景天(SedumalfrediiHance,景天科景天属,一种生长在浙江某一古老铅锌矿区土壤上的新锌超积累植物)的生长及其对锌和镉的吸收积累特性的影响。结果表明,Zn/Cd=500/100μmol·L-1下,植物生长最佳。镉、锌在东南景天体内的含量随着镉、锌处理浓度的提高而提高。锌在植物体内的分布为茎>叶片>根系,在Zn/Cd=1000/50μmol·L-1处理水平植株体内锌含量达到最大,其中茎中锌含量为23.2mg·g-1;而镉在植株体内分布则为叶片>茎>根系,在Zn/Cd=50/400μmol·L-1处理水平镉含量达到最大,其中叶片中镉含量为12.1mg·g-1。在一定处理范围内,锌的加入促进了植物对镉的吸收和积累,但镉的加入对植物体内锌的积累没有显著影响。高锌或高镉处理均抑制了植物对锌和镉的吸收和积累。表明东南景天不仅可以忍耐锌镉复合污染,还具有一定的超量积累锌和镉的能力。更多还原

【Abstract】 Sedum Aftredii Hance has been found to be a native Zn -hyper-accumulating plant species in Chin a.In the present study,responses and metal accumula tion of Sedum afredii Hance were examined under cadmium /zinc co mplex polluted conditions.The results showed that little reduction in growth was found when the plan t was grown at Cd /Zn levels of 500/100μmol·L -1 .The concentrations of Cd and Zn in leaves and stems of Sedum Afredii H increased with increase of Zn /Cd levels.The distribution of Zn in different plant parts was:stem>l eaf>root,whereas that of Cd in an ord er:leaf>stem>root.The highest con centrations of Zn(23.2mg ·g -1 )and Cd(12.1mg ·g -1 )were attained by the plants at Zn /Cd l evels of 1000/50and 50/400μmol·L -1 treatments,respectively.The upta ke and accumulation of Cd in plant were enhanced by decreasing the concent rations of Zn in the culture solutions,while Cd had no similar function.When the concentrations of Cd and Zn in the culture soluti ons were higher,the uptake and accumulation of Zn and Cd i n plants decreased.The results indi cated that Sedum Afredii H is not only a Zn -hyper -accumulating plant specie,but also a Cd -hyper -accumulating plant spec ie,which may provide a very availabl e material for studying on the mechanism of metal uptake and accumulation by plant under Cd /Zn complex polluted conditions.Besides,from phytoremediation perspective,Sedum Afredii H seems to be perfect plant for the extr action of Zn and Cd from the contaminated soil.更多还原