植物激素协同螯合剂对蓖麻修复Cd污染土壤的影响

Effects of phytohormone and chelating agents on remediation of cadmium contaminated soil using Ricinus communis L.

【目的】通过研究螯合剂(EDTA)协同外源激素(IAA、ABA)对蓖麻富集Cd的强化效果,以期提高蓖麻对镉(Cd)污染土壤的修复效率。【方法】以滇蓖2号为试验材料,通过盆栽试验,探究螯合剂(EDTA)和植物激素吲哚乙酸(IAA)、脱落酸(ABA)施用对Cd污染土壤的蓖麻株高、地下部分干重、地上部分干重、Cd吸收及土壤Cd提取率的影响。【结果】单独添加IAA或ABA均能促进蓖麻的生长,使其生物量较对照分别增加18.35%和5.79%,单独添加EDTA能够抑制蓖麻的生长,使其生物量较对照减少22.30%。EDTA和植物激素单施与配施对蓖麻各器官Cd含量和积累量的影响不同。与对照相比,单施EDTA、IAA及EDTA与IAA、ABA配施均显著提高了蓖麻体内的Cd含量及积累量,其中表现最好的为EDTA与10 mg/kg IAA配施,其根、茎、叶的Cd含量较对照分别提高105.90%、76.15%和524.74%,蓖麻整株的Cd积累量较对照提高329.63%。施用EDTA和植物激素对蓖麻各器官Cd的转运系数也有不同影响。EDTA、IAA单施及EDTA与IAA、ABA配施均可以提高蓖麻对土壤中Cd的提取效率,其中EDTA与10 mg/kg IAA配施时提取效率最高,为1.16%。【结论】在修复Cd污染土壤中,外源激素协同螯合剂可以强化蓖麻对土壤中Cd的富集和移除效果。

【Objective】The strengthening effect of chelating agent(EDTA)and exogenous hormone(IAA,ABA)on the enrichment of Cd in castor was studied in order to improve the remediation efficiency of castor on Cd-contaminated soil.【Method】The cultivar,Dianbi 2 was used as experimental materials.The study investigated the effects of chelating agent(EDTA),indoleacetic acid(IAA)and abscisic acid(ABA)on plant height,underground dry weight of plants,above-ground dry weight,Cd absorption and Cd extraction rates of castor on Cd-contami-nated soil in a pot experiment.【Result】The addition of IAA or ABA alone promoted the growth of castor,but the biomass increased by 18.35%and 5.79%respectively compared with the control.Adding EDTA alone inhibited the growth of castor,and the biomass decreased by 22.30%compared with the control.The effects of EDTA and phytohormones on the concentrations and accumulation of Cd in various or-gans of castor were different.Compared with the control,applying EDTA or IAA alone,and EDTA combined with IAA and ABA significantly increased the content and accumulation of Cd in castor,and the combination of EDTA and 10 mg/kg IAA had the best performance,which increased the Cd content in roots,stems and leaves by 105.90%,76.15%and 524.74%,respectively.The Cd accumulation in the whole plant of castor increased by 329.63%compared with the control.The chelating agent(EDTA)and phytohormone(IAA and ABA)had dif-ferent effects on the Cd transfer factor of castor.Application of EDTA and IAA alone and combined application of EDTA with IAA and ABA improved the extraction efficiency of Cd in the soil,and the extraction efficiency of EDTA combined with 10 mg/kg IAA being the highest,which was 1.16%.【Conclusion】In the remediation of severely Cd-polluted soil,phytohormone(IAA and ABA)and chelating agent(EDTA)application strategy can enhance the effect of castor on Cd accumulation in plants and removal in the soil.