硫对超积累植物东南景天生长和镉累积的影响

通过营养液培养试验研究了不同硫镉水平对超积累东南景天生长和镉累积的影响。结果表明,不同处理下东南景天根、茎和叶片的生物量、镉含量、镉累积量均以叶片>茎>根,且以Cd100>Cd10,显示出东南景天对镉的超积累特性。供硫1.5~2.25 mmol/L显著提高超积累东南景天根、茎和叶片的生物量、镉含量、镉累积量及整株镉累积总量。超积累东南景天地上部分(叶片 茎)镉累积量/地下部分(根)镉累积量的比值(S/R)远大于1,表明东南景天植株体内可能存在"增硫诱导镉需求"现象,而从植物修复角度来说,利用增硫手段提高超积累东南景天生长和地上部镉的积累能力具有重要的应用价值。超积累东南景天Cd的吸收速率和转运速率随营养液中硫(S)浓度的增加而增加,二者可分别用对数方程和直线方程来描述。

Effects of Sulfur on Growth,Cadmium Absorption and Accumulation in Hyperaccumulator-Sedum alfredii Hance

The effects of sulfur on growth,cadmium absorption and accumulation in hyperaccumulator-Sedum alfredii Hance were investigated in hydroponic culture.Biomass,Cd contents and amounts of Cd accumulated of leaves,stems and roots of Sedum alfredii Hance were in the order of leaves>stems>roots and Cd100>Cd10,showed Sedum alfredii Hance hyperaccumulated charactreristics of Cd.With increasing S supplies from 1.5 to 2.25 mmol/L,biomass,Cd contents,amounts of Cd accumulated in leaves,stems and roots,total amounts of Cd accumulated of Sedum alfredii Hance were increased significantly.It was also found that there were a higher ratio of shoot Cd accumulation /roots Cd(S/R>1) in any S and Cd treatments,suggesting that appropriate S application enhanced Cd absoption,translocation from root to shoot in Sedum alfredii Hance.From these results indicated that "sulfur-induced Cd requirement"was evident in Sedum alfredii Hance.With respect to phytoremediation,the application of S at appropriate rates may be useful approach to enhancing the growth and Cd accumulation in Sedum alfredii Hance for phytoremediation of the Cd-contaminted soils.Cd uptake efficiency and translocation efficiency of Sedum alfredii Hance were increased with increasing S supplies and the relationship coluld be described by logarithmic equation and linear equation,respectively.