东南景天组培苗对锌、镉及其复合污染土壤的修复效能分析

东南景天（Sedum alfredii Hance）是一种典型的Zn、Cd、Pb的超积累植物，也是一种极佳植物修复材料．本文采用盆栽实验方法，研究东南景天组培苗在几种不同Zn、Cd污染土壤上的生长情况，及其对土壤Zn、Cd的去除效果．预期研究结果可为今后利用东南景天组培苗治理Zn、Cd污染提供一些理论依据．取得主要研究结果:1）东南景天组培苗完整地保留了扦插苗对于重金属的耐受性，并且对于高质量分数的Zn、Cd的环境适应性更强．在3#污染土壤（w（Zn）约2 000 mg·kg?1）中，组培苗地上部分生物量是对照组的2.3倍；在4#污染土壤（w（Cd）约1344 mg·kg?1）中，组培苗地上部分生物量相比于对照组的生物量增加了16.4%．2）东南景天组培苗对复合污染土壤中的Zn、Cd有很强的吸收积累能力．在1#和2#复合污染土壤中，组培苗对Zn的富集系数分别达到9.69和11.09，对Cd的富集系数分别达到12.67和85.36．3）复合污染土壤中的Zn、Cd会发生一定的交互作用，从而影响东南景天组培苗对Zn、Cd的吸收和富集．土壤中低质量分数的Cd会促进植物对Zn的吸收，但Zn却会抑制植物对Cd的吸收富集．此外，生长在复合污染土壤中的东南景天组培苗体内Zn、Cd重金属的分布也会受到影响． 

Remediation by tissue culture seedlings of Sedum alfredii Hance in Zn-,Cd-and combination-contaminated soils

Sedum alfredii Hance is a typical hyperaccumulator of zinc, cadmium and lead, and is excellent for phytoremediation．In this work Sedum alfredii Hance seedlings were pot cultured in Zn- and Cd-contaminated soils, and removal of Zn and Cd was examined．Tissue culture seedlings were found to preserve completely tolerance to heavy metals, environment adaptability to high concentrations of Zn and Cd was stronger than cut seedlings．In heavily contaminated soil (Zn 2000 mg·kg?1), biomass of tissue culture seedlings was 2.3 times that of control (cut seedlings)．In Cd-contaminated soil (Cd 1344 mg·kg?1), biomass of tissue culture seedlings increased by 16.4% compared to control．Tissue culture seedlings showed strong ability to absorb and accumulate Zn and Cd in compound-contaminated soil．In 2 compound-contaminated soils, enrichment coefficient for Zn was 9.69 and 11.09, for Cd was 12.67 and 85.36, respectively．Zn and Cd in composite contaminated soil were found to interact, which affected absorption and enrichment of Zn and Cd．A low Cd concentration in soil promoted Zn absorption, but Zn inhibited absorption and enrichment of Cd．Distribution of Zn and Cd heavy metals in plants growing in compound-contaminated soil is affected．