贵州万山汞矿地区耐汞野生植物研究

在贵州万山地区废弃汞矿堆和矿山附近,受长期高剂量汞暴露的影响经过的自然选择,该地区出现了一些能耐受汞毒性的生态型植物。对汞耐受及汞富集植物的筛选对于汞污染土壤的植物修复具有一定的现实意义。通过对万山梅子溪地区汞污染土壤及汞耐受植物采样调查发现,该区域采样土壤中汞的含量均在50 mg·kg-1以上,达到重度汞污染水平。对该地区野生植物的采样分析发现,蔷薇科植物悬钩子不仅数量较多,单株植物生物量较大,表现出很强的耐汞毒性的能力,而且植株内可以很大程度地富集汞,在其植株中汞的含量可达20 mg·kg-1左右,属于汞富集植物,另外发现野蒿对汞也具有较强的富集能力,其植株中汞的含量可达10 mg·kg-1以上。该类型植物的发现将为植物的汞耐受以及汞富集机理研究提供新的素材,为汞污染土壤的植物修复技术提供新的植物类型,也为进一步开发汞污染土壤处理技术提供了一种可能。

Study of Mercury Resistant Wild Plants Growing in the Mercury Mine Area of Wanshan District, Guizhou Province

With a long-term exposure to high levels of mercury (Hg), Hg-resistant wild plants were naturally selected to survive in the region near the abandoned Hg mine area in Wanshan District, Guizhou Province. The screening of Hg-resistant and -hyperaccumulation plants is practically significant for the phytoremediation of Hg contaminated soils. The concentrations of Hg in the soils and wild plants collected from Meizi rivulet in Wanshan district were analyzed. The results indicated that the contents of Hg in most of the soils surpassed 50 mg·kg^-1which reached severe degree of Hg contamination. The concentration of Hg in Rubus L. which was found to have a large biomass survived in the Hg contaminated area can reach up to 20 mg·kg^-1. Rubus L. can be considered as one of the Hg resistant and enriched plants. Additionally, the concentration of Hg in Artemisia argyi H. can also reach up to 10 mg·kg^-1 or more, indicating a strong capability for accumulating Hg of this plant. The Hg-resistant and Hg-hyperaccumulation plants discovered in this study can provide new model plants for revealing the mechanisms of Hg resistance and Hg accumulation in plant, and new insights for improving the phytoremediation techniques in Hg contaminated soils.