【摘要】 通过对广西某电镀厂附近的植物和土壤的野外调查,发现了湿生铬超积累植物———李氏禾(Leersia hexandraSwartz)。结果表明,多年生禾本科李氏禾对铬具有明显的超积累特性,叶片内平均铬含量达1786.9mg/kg,变化范围为1084.2~2977.7mg/kg;叶片内铬含量与根部土壤中铬含量之比最高达56.83,叶片内铬含量与根茎中铬含量之比最高达11.59,叶片内铬含量与水中铬含量之比最高达517.86。李氏禾不仅对铬有很强的富集能力,而且具有生长快、地理分布广、适应性强的特点,因此李氏禾的发现将为植物的铬超积累机理与铬污染环境的植物修复研究提供新的重要物种。更多还原

【Abstract】 In a series of field investigations and plant samplings around an electroplating factory in Guangxi Province,a hygrophyte with chromium hyper-accumulative properties,Leersia Hexandra Swartz,was found for the first time in china.Leersia Hexandra Swartz is a perennial species that often grows along the margins of the tailing pond of the electroplating factory and the nearby streams.It grows to about 1m tall but when floating,it may have branches several meters long.Further research indicated that the hygrophyte from the tailing pond was obviously characterized by the chromium enrichment in its leaves,with a mean Cr concentration of 1786.9mg/kg(1084.2～2977.7mg/kg).Its rootstalks had an average Cr concentration of 236.6mg/kg(135.2～386.1mg/kg),whereas the Cr concentrations in the silt and water of the pond were determined to be 114.3mg/kg and 5.90mg/L,respectively.The highest ratio of Cr concentration in its leaves to that in soil around its roots was 56.83,the highest ratio of Cr concentration in its leaves to that in its roots was 11.59 and the highest ratio of Cr concentration in its leaves to that in water was 517.86. The results indicated that Leersia Hexandra Swartz could significantly absorb chromium from the silt and water and enrich its leaves,stems and roots.In addition to its Cr hyper-accumulator characteristics,Leersia Hexandra Swartz is known to grow quickly,to be highly adaptable and is found over a wide geographical area.Therefore,this hygrophyte shows potential as a very successful phytoremedy in treating Cr-contaminated soil and water.Furthermore,its discovery provides a new plant for the investigation of the Cr hyper-accumulation mechanism.更多还原