促根剂及水分胁迫对Cd污染异质土壤中小麦吸收、转运Cd的影响  

Effects of root agent and water stress on wheat root elongation and Cd uptake and translocation in heterogeneous Cd contaminated soil

作　　者：雷小琴 王萌[1] 郑涵[1] 李杉杉 陈世宝[1] LEI Xiaoqin;WANG Meng;ZHENG Han;LI Shanshan;CHEN Shibao(Key Laboratory of Plant Nutrition and Fertilizer,Ministry of Agriculture and Rural Affairs,Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]农业农村部植物营养与肥料重点实验室,中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《地学前缘》2019年第6期95-102,共8页Earth Science Frontiers

基　　金：中央级公益性科研院所基本科研业务费专项(1610132018041);国家重点研发计划项目(2016YDF0800707)

摘　　要：为了研究促根剂与水分胁迫诱导小麦根伸长及其降低小麦对异质土壤中Cd吸收转运的影响,本研究制备了不同浓度Cd污染土壤,利用根箱法设置了3种不同土层(0~6cm、7~12cm及13~18cm)下的Cd污染异质土壤,研究了3种添加比例(0.1%、0.2%和0.4%)下促根剂与3种水分胁迫诱导(60%、50%和40%MWHC)下小麦根伸长对降低小麦Cd吸收、转运的影响。结果表明:不同促根剂与水分胁迫诱导处理可以明显促进小麦根系生长,表现为小麦根系总长与根表面积的显著增加,其中促根剂促使下层(13~18cm)土壤中小麦根系总长增加了63.2%~205.9%,水分胁迫诱导增加了69.1%~91.2%。不同促根剂处理可以不同程度增加小麦分蘖数,从而增加了小麦籽粒生物量(小麦籽粒生物量增加5.6%~50.3%);与对照相比,除了40%MWHC水分处理(WS3)外,不同促根剂与水分胁迫处理可以显著降低(P<0.05)Cd污染异质土壤中小麦茎叶与籽粒中Cd的浓度,降低范围分别为24.0%~41.5%和23.0%~42.7%,其中以添加0.4%促根剂处理效果最佳,不同处理对降低小麦籽粒Cd含量效果顺序为RA3≈RA2>WS2≈RA1≈WS1>WS3。基于上述结果,RA2和WS2在Cd异质污染农田修复中具有较大的应用价值。We investigated the influence of root agent and water stress on root elongation of wheat,and Cd uptake and translocation by wheat,in heterogeneous Cd-contaminated soil.We prepared heterogeneous Cd contaminated soils at three soil depths(0-6,7-12 and 13-18 cm)using rhizobox method.In a whole growth culture experiment,we studied the effect of root agent at three addition levels(0.1%,0.2%and 0.4%),and the effect of three water stress treatments(60%,50%and 40%MWHC(maximum water holding capacity)),on Cd uptake and translocation by wheat.The results indicated that root growth of wheat,compared with control,was enhanced by both treatments which significantly increased the total root length(cm)and root surface(cm^2).In detail,the total root length in the subsoil(13-18 cm depth)increased by 63.2%-205.9%and 69.1%-91.2%by root agent and water stress treatments,respectively.Root agent application promoted the wheat tillering numbers and increased the biomass of wheat grain by 5.6%-50.3%.In terms of Cd uptake by wheat,the result showed that,except the 40%MWHC water stress treatment(WS3),Cd concentrations in shoots and grain of wheat were significantly decreased(P<0.05)by both treatments.Compared with control,the decreases ranged in 24.0%-41.5%and 23.0%-42.7%,respectively,with the best effect observed at the 0.4%additional level for root agent.The effect of different treatments on the Cd decrement in wheat grain followed the order of RA3≈RA2>WS2≈RA1≈WS1>WS3.Based on the above results,we concluded that root agent and water stress treatments can be recommended for remediation of field soils contaminated by heterogeneous heavy metals.

关 键 词：CD污染土壤 促根剂 水分胁迫 小麦 根伸长 

分 类 号：X53[环境科学与工程—环境工程]