短毛蓼对Cd的富集特性研究（摘要）（英文）

目的]研究锰超富集植物短毛蓼（Polygonum pubescensBl.）对重金属镉的响应和富集特征。方法]采用Hoagland营养液为培养基质,设定8种镉处理浓度（0、25、50、100、200、500、800、1 000 mg/L）。植株收获后用自来水洗净,记录植物株高、根长,然后将根浸入20 mmol/LEDTA-Na溶液中交换15 min,以去除根系表面吸附的金属离子,最后再用去离子水冲洗3次,用吸水纸吸干表面水分。将植物分为根、茎、叶放至烘箱内,在105℃下杀青30 min,然后在70℃下烘48 h,测定植物各部分干质量,最后用不锈钢粉碎机磨细,过60目尼龙网筛。植物样品采用微波消解法用HNO3＋H2O2消解。重金属镉含量的测定采用火焰原子吸收分光光度法（WFX-110型）。结果]随着培养液中镉浓度的增加,短毛蓼的株高、根长及生物量均呈下降趋势,但在较低浓度（25、50 mg/L）下与对照相比差异均不显著（P〉0.05）,在较高浓度下（100 mg/L以上）短毛蓼总干重明显减少,差异显著（P〈0.05）,表明短毛蓼受Cd毒害影响较明显;在试验设定的各种镉处理水平下,短毛蓼根和地上部Cd含量均超过100 mg/kg,Cd富集系数均大于1,当培养液中镉浓度为1 000 mg/L时,地上部镉含量高达3 070.069 mg/kg,根中镉含量高达4 863.96 mg/kg。随着镉处理浓度的增加,短毛蓼对镉的吸收量呈现先增加后降低的趋势,当镉处理浓度为800 mg/L时,根和地上部的镉吸收量均达最大值,分别为878.88 mg/株和2 302.91 mg/株。在试验各处理水平下（CK除外）短毛蓼根和地上部均表现出较强的镉富集能力,根对镉的富集系数为4.86 ～55.88,地上部富集系数为2.72 ～6.52;从转运量系数来看,除对照外,各处理水平下转运量系数为0.73 ～4.95;当Cd处理浓度大于50 mg/kg时,转运量系数超过1。结论]短毛蓼对镉具有较强的耐受性和富集能力,在镉污染土壤的植物修复中具有一定的应用潜力。

Accumulation Characteristics of Cd in Polygonum pubescens Bl

Objective] The research aimed to study the response and accumulation characteristics of Cd in Polygonum pubescens Bl.Method] Taking Hoagland nutritional solution as the culture substrate,eight kinds of Cd concentrations （0,25,50,100,200,500,800,1 000 mg/L） were set up.Result] Under low concentrations of Cd （25 and 50 mg/L）,the biomass of P.pubescens had no significant difference with CK （P0.05）.Under all the test concentrations of Cd,Cd content in the roots and shoots of P.pubescens exceeded 100 mg/kg and the enrichment coefficients of Cd were over 1.With the increasing of Cd concentration,Cd content and Cd accumulation amount in P.pubescens increased significantly.When Cd concentration exceeded 50 mg/L,translocation capacity coefficient was greater than 1.Conclusion] Polygonum pubescens has high tolerance and accumulation capacity of Cd,and it may has some potential on the phytoremediation of Cd-contaminated soil.