我国西南地区代表性蔬菜对重金属的积累特征

Heavy Metal Accumulation in the Representative Vegetables in Southwest China

为比较分析我国西南地区代表性蔬菜对重金属的积累能力,优化污染区作物种植结构,以昆明市呈贡区为例,在35个典型蔬菜种植区共采集101对土壤-蔬菜样品,对19种蔬菜食用部分和种植土壤中的As、Cd、Cr、Cu、Pb和Zn含量进行了测定,通过计算重金属富集系数,并利用协方差分析,比较了不同种类蔬菜对重金属的积累特征.结果表明,不同种类蔬菜具有不同的重金属积累能力,叶菜类蔬菜对Cd和Pb的积累能力显著高于瓜果类和根茎类(P<0.05);根茎类蔬菜对Cr和Cu的积累能力显著高于其他两类蔬菜(P<0.05).白菜和香菜对Cd的积累能力较强,空心菜对Pb的积累能力较强,而茼蒿对Zn的积累能力较强.土壤pH与蔬菜中的Cu和Zn含量呈显著负相关.因此,不同种类蔬菜对重金属的积累能力存在明显差异,应根据土壤污染特征,因地制宜调整蔬菜种植结构,以保障蔬菜品质安全和人体健康.

In order to compare the accumulation capacity of representative vegetables to heavy metals in southwest China and select proper crops to cultivate in polluted areas,101 vegetable-soil samples,including 19 representative vegetable species,from 35 typical crop planting areas in Chenggong District,Kunming were collected,and the contents of As,Cd,Cr,Cu,Pb,and Zn in soil and vegetable were measured.The differences of the capacity in heavy metal accumulation of different vegetables were compared by covariance analysis and calculating enrichment factor.The results showed that there were significant differences in the accumulation ability of heavy metals among different vegetables.The accumulation ability of leaf vegetables to Cd was significantly higher than that of fruit and rhizome vegetables(P<0.05).The accumulation of Cr and Cu in rhizome vegetables was significantly higher than the other two types of vegetables(P<0.05).Chinese cabbage and coriander have strong ability to accumulate Cd,and water spinach has a strong ability to accumulate Pb,and crown daisy has a strong ability to accumulate Zn.In general,different vegetables have different capacity in the accumulation of different heavy metals,so proper vegetables should be selected for planting according to soil pollution characteristics to ensure vegetable quality and human health.