江西宜春市明月山地区土壤和多种作物中硒的含量及形态分布特征

Content and speciation distribution of selenium in soil and crops in Mingyue Mountain area of Yichun City,Jiangxi Province

硒在土壤-作物系统中的分布特征是天然硒生物营养强化国际合作计划的重要基础.为了调查天然富硒区土壤与农作物中硒的积累特征和分布规律,本研究采集并测定宜春明月山地区土壤和农作物硒含量,利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)测定农作物中5种硒形态含量.结果表明,土壤总硒含量为167~905μg/kg,中位值为373μg/kg,生物可利用硒含量为32~127μg/kg,中位值为53μg/kg;农作物中水稻、蔬菜、水果、茶叶的硒含量分别为9~210、23~282、1~20、30~221μg/kg;不同种类农作物中硒的形态组成不同,水稻中有机硒所占比例为83%,主要为SeMet;蔬菜样品中,茄子、辣椒、空心菜有机硒所占比例分别为45%、65%、68%,硒赋存形态为SeMet、MeSeCys和SeCys2;茶叶样品中有机硒占比为47%,主要以Se(VI)、MeSeCys形态存在.总体而言,宜春明月山地区土壤总硒和生物可利用硒含量高,农作物总硒含量高、硒赋存形态好,辣椒、空心菜、水稻等可作为天然富硒农作物的推荐种植品种.

The distribution of selenium in the soil-crop system is an important basis of the international NBP(Natural Selenium Biofortification Program).In order to investigate the accumulation and distribution of selenium in soil and crops in natural selenium-rich areas,samples of soil and crops in Mingyue Mountain area of Yichun were collected.The contents of selenium in soil and crops were determined by atomic fluorescence spectrometer(AFS),and the contents of five selenium species in crops were determined by high-performance liquid chromatography inductively coupled plasma mass spectrometry(HPLC-ICP-MS).The results showed that the total content of selenium in soil was 167−905μg/kg,and the median value was 373μg/kg,which was higher than the national background average of soil selenium content.The bioavailable selenium content in soil was 32−127μg/kg,and the median value was 53μg/kg.The selenium content of crops such as rice,vegetables,fruits and tea were 9−210,23−282,1−20 and 30−221μg/kg,respectively.According to the standard for selenium enrichment in Jiangxi Province,all vegetable samples and some rice,tea and fruit samples were Serich agricultural products.The speciation composition of selenium in different crops was different.The proportion of organic selenium species in rice was 83%,and most of them existed in the form of SeMet.With the increase of total selenium content in rice,the proportion of organic selenium increased.The proportions of organic selenium species(SeMet,MeSeCys,and SeCys2)in vegetable samples such as eggplant,pepper,and water spinach were 45%,65%,and 68%,respectively.In tea samples,the proportions of organic selenium species were 47%,and the predominant selenium species were Se(VI),MeSeCys,and SeCys2.In conclusion,the contents of soil total selenium and bioavailable selenium in Mingyue Mountain are abundant,and crops such as pepper and water spinach accumulating abundant selenium and good selenium species are suggested to be cultured in this area.Rice can improve the total selenium content through biological nutrition enhancement technology.Eggplant and tea have a large proportion of inorganic selenium,which should be paid attention to when human body ingests,so they are not suitable for selenium rich crops.This study systematically investigated the content and species of selenium in the soil and crops in Mingyue Mountain,Yichun,which is conducive to the efficient development and utilization of selenium rich soil resources,and will provide a scientific basis for the development of high-quality and characteristic agricultural products of selenium-rich in Yichun.