杨梅树体中重金属元素的分布特征

Distribution Characteristics of Heavy Metals in Myrica rubra

对试验点土壤及荸荠种杨梅（Myrica rubra）的根、枝条、叶片、果实进行了铜（Cu）、镉（Cd）、铅（Ph）、汞（Hg）和砷（As）含量的检测。结果表明，采样点土壤中均检测出Cu、Cd、Pb和As，而Hg未检出；检出的重金属在O～20cm、20—40cnl土层中均有不同程度存在，表层土壤的重金属含量高于深层土。Cd、Hg、Pb、Cu在杨梅根、枝、叶、果实中均检出。而As只在果实中被检出；不同重金属元素在杨梅树体同一器官中的含量存在明显差异，其中一年生枝除了Hg外，其余3种重金属含量均明显高于其他器官。同一种重金属在不同器官中的分布也存在明显差异．Pb和Cu的分布呈现出一年生枝〉二年生枝〉二年生枝老叶〉一年生枝新叶〉二年生根〉果实的相同特征．Cd主要分布在一年生枝和二年生根当中．Hg则主要分布在叶片中。

The contents of Cu, Cd, Pb, Hg and As in the soil and Myrica rubra cv. BiQi in the experimental site were measured. Results showed that soil in the experimental site contained Cu, Cd, Pb and As, with no trace of Hg. Heavy metals existed in the soil layers of 0-20 cm and 20-40 cm. The contents of heavy metals in the .surface layer were higher than that in the deeper layers. Cd, Hg, Pb and Cu were found in the roots, branches, leafs and fruits. As only existed in fruits. The contents of different elements were significantly different in the same organ. Except for Hg, the contents of other 3 heavy metals in the one-year branches were significantly higher than that in other organs. The contents of the same heavy metal in different organs were significantly different. The contents of Pb and Cu in different organs were in the order of one-year branch〉two-year branch〉old leaf of two-year branch〉new leaf of one-year branch〉two-year root〉fruit. Cd was distributed mainly in one-year branches and two-year roots. Hg was distributed mainly in leafs.