重金属Cd在树仔菜-土壤系统中的富集迁移及安全阈值研究  

Accumulation and transformation of heavy metal Cadmium in Sauropus androgynus-soil system and its safety thresholds

作　　者：范琼[1] 冯剑 邹冬梅[1] 酒元达 苏初连 吴小芳[1] 吴彬 赵敏[1] FAN Qiong;FENG Jian;ZOU Dongmei;JIU Yuanda;SU Chulian;WU Xiaofang;WU Bin;ZHAO Min(Analysis and Testing Center,Chinese Academy of Tropical Agricultural Sciences/Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables/Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable,Ministry of Agriculture and Rural Affairs,Haikou 571101,Hainan,China)

机构地区：[1]中国热带农业科学院分析测试中心·海南省热带果蔬产品质量安全重点实验室·农业农村部亚热带果品蔬菜质量安全控制重点实验室,海口571101

出　　处：《中国瓜菜》2022年第11期86-92,共7页China Cucurbits And Vegetables

基　　金：海南省自然科学基金(320QN301);海南省热带果蔬产品质量安全重点实验室开放课题(KFKT2021001);五指山市生态科技特派员项目(WZSKTPXM2021006)。

摘　　要：为建立树仔菜产地土壤的镉(Cd)安全阈值,保障树仔菜安全生产,通过盆栽试验分析树仔菜在不同Cd浓度土壤下对Cd的富集迁移规律,利用相关性分析和多元线性回归分析等方法研究树仔菜Cd迁移积累的关键环境制约因子,建立树仔菜可食部位与土壤Cd总量的模型,推导出树仔菜土壤的Cd安全阈值。结果表明,树仔菜的积累系数大于1,当土壤Cd浓度(w,后同)<0.28 mg·kg^(-1)时,树仔菜各部位积累表现为叶>茎>根>嫩梢,迁移系数大小为TF2>TF3>TF1>TF4;当Cd浓度为0.28 mg·kg^(-1)时,树仔菜各部位积累顺序为根>叶>茎>嫩梢;Cd浓度≥0.65 mg·kg^(-1)时,树仔菜各部位迁移系数顺序为TF1>TF3>TF2>TF4,说明树仔菜是一种易富集土壤Cd的蔬菜。但随着土壤Cd浓度增加,Cd从根部和茎部向叶子迁移能力逐渐下降,在根部富集较多。除了土壤Cd总量的影响外,土壤pH值和Cd有效态含量是影响树仔菜Cd积累的关键因子;通过树仔菜可食部位的Cd含量与土壤Cd总量构建回归模型推导出树仔菜土壤Cd安全阈值为0.087 mg·kg^(-1),远低于现行标准,为树仔菜安全种植和风险管控提供了理论依据。To build the Cd safety threshold of Sauropus androgynus soil and ensure its safe production,in this study a pot experiment with different Cdconcentration were used to analyze regularities of Cd accumulation and migration of Sauropus androgynus.Correlation analysis and multiple linear regression analysis were used to study the key environmental constraints of Cd accumulation and migration.Cd safety thresholds were calculated by the regression models between the Cd concentration in edible parts of S.androgynus and soils.The results indicated the accumulation coefficient of S.androgynus was greater than 1,when the soil Cd concentration was less than 0.28 mg·kg^(-1),the accumulation of S.androgynus in various parts showed as follows:leaf>stem>root>tender shoot,Cd transformation coefficients of S.androgynus was TF2>TF3>TF1>TF4,when Cd concentration was 0.28 mg·kg^(-1),the accumulation order of each part of S.androgynus was root>leaf>stem>tender shoot.When Cd concentration>0.65 mg·kg^(-1),the order of Cd transformation coefficients was TF1>TF3>TF2>TF4,indicating that S.androgynus is a kind of vegetable that is easy to accumulate soil Cd.However,with the increase of soil Cd concentration,the ability of Cd migration from roots and stems to leaves gradually decreased,and it was more accumulated in roots.Expect for soil Cd content,the soil pH value and available Cd content were the key factors affecting Cd accumulation in S.androgynus.The Cd content of S.androgynus and soil Cd content build the regression analysis method,which was used to calculate the safety threshold of Cd in soil were 0.087 mg·kg^(-1),which was far lower than the current standard.The results provided a theoretical basis for the safe planting and risk control of S.androgynus.

关 键 词：树仔菜 镉 富集 迁移 安全阈值 

分 类 号：S636.9[农业科学—蔬菜学]