矿区Cu耐性植物研究初探

Primary Study on Copper Tolerant Plants in Mine Areas

对长江沿岸几个主要Cu矿区的植被及其Cu含量分布进行了调查分析,并且通过多批次室内培养试验研究了几种候选植物品种对Cu的富集效果。结果表明,虽然在矿区被调查植物中仍没有发现具有严格意义上的Cu超富集植物,但是由于鸭跖草(CommelinacommunisL.)和杠板归(Polygonumperfoliatum)对Cu均有较多吸收,其中杠板归在一定条件下其地上部累积Cu的含量能够超过1000mg·kg-1,较鸭跖草高,表现出非常强的吸收Cu的能力,所以具有很好的应用前景。盆栽试验发现,鸭跖草和杠板归对Cu均具有很好的耐性,溶液Cu浓度达400μmol·L-1时2种植物均仍能正常生长。另外,EDTA可以显著增加鸭跖草对土壤Cu的吸收,但对其生长有明显抑制。

Copper tolerant plants were surveyed in several copper mines of southern China along Yangtse river, and a series of pot experiments of Commelina communis L. and Polygonum perfoliatum in glasshouse were performed to evaluate their possibilities in repairing Cu contaminated soil. The survey results showed that no plant was yet found in these areas to strictly meet the definition of Cu hyperaccumulator, and the Cu concentrations in the aboveground parts of Elsholtzia splendens, Commelina communis L. and Polygonum perfoliatum were in the range of 34～414, 119～1589 and 88～1122 mg·kg-1, with the average 121, 554 and 310 mg·kg-1, respectively. Commelina communis L. and Polygonum perfoliatum were very tolerant to Cu toxicity in a culturing solution with Cu concentration up to 400 μmol·L-1. The uptake of Cu by Commelina communis L. and Polygonumperfoliatum from Cu contaminated soil or the culturing solution was very high, in which the ability of Cu uptake of Polygonum perfoliatum was stronger than Commelina communis L. In some cases, Cu concentration in Polygonum perfoliatum was above 1 000 mg·kg-1, the threshold for a Cu hyperaccumulator. The presence of EDTA enhanced Cu uptake of Commelina communis L., but was disadvantageous for its growth to some degree.