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为了解不同重金属处理烟草中重金属的累积及分布特征,进行了高、中、低浓度的砷(As)、镉(Cd)、汞(Hg)、铅(Pb)及其复合处理盆栽试验。结果表明:烟叶中As、Cd和Pb元素含量随时间变化规律为:初期>收获期、中期,Hg为中期>收获期>初期。重金属污染胁迫下,烟草中重金属累积分布特征为:As和Pb为根>茎>叶,Cd为茎>根>叶,Hg为根>叶>茎(对照:叶>根>茎)。烟草中重金属(除Hg)含量总体随外源添加浓度的增大而显著增大(p<0.05)。复合处理烟叶中重金属含量低于单元素处理。烟叶中重金属增幅顺序为As>Cd>Pb>Hg,As和Cd处理间烟草(根、茎和叶)中As和Cd含量均差异显著。可见,烟草对土壤As和Cd污染最为敏感,烟草种植时应尽量选择土壤As和Cd含量较低的区域以避免其过度累积。
In order to understand the accumulation and distribution of heavy metals in different heavy metals, pot experiments were carried out with high, medium and low concentrations of As, Cd, Hg and Pb. The results showed that the content of As, Cd and Pb in tobacco leaves changed with time as follows: initial period> harvest period, mid period, Hg middle stage> harvest period> initial stage. Under the heavy metal pollution stress, the distribution characteristics of heavy metals in tobacco were as follows: As and Pb were root> stem> leaf, Cd was stem> root> leaf, Hg was root> leaf> stem (control: leaf> root> stem). The contents of heavy metals (except Hg) in tobacco increased with the increase of exogenous concentrations (p <0.05). The content of heavy metals in the composite leaves was lower than that of the single element treatment. The order of increase of heavy metals in tobacco was As> Cd> Pb> Hg. As and Cd contents in tobacco (roots, stems and leaves) were significantly different between As and Cd treatments. It can be seen that tobacco is the most sensitive to soil As and Cd pollution. When planting tobacco, the areas with lower As and Cd contents should be chosen so as not to over-accumulate.