title: Chromium accumulation by the hyperaccumulator plant Leersia hexandra Swartz.
abstract: Leersia hexandra Swartz (Gramineae), which occurs in Southern China, has been found to be a new chromium hyperaccumulator by means of field survey and pot-culture experiment. The field survey showed that this species had an extraordinary accumulation capacity for chromium. The maximum Cr concentration in the dry leaf matter was 2978 mg kg(-1) on the side of a pond near an electroplating factory. The average concentration of chromium in the leaves was 18.86 times as that in the pond sediment, and 297.41 times as that in the pond water. Under conditions of the nutrient solution culture, it was found that L. hexandra had a high tolerance and accumulation capacity to Cr(III) and Cr(VI). Under 60 mg l(-1) Cr(III) and 10 mg l(-1) Cr(VI) treatment, there was no significant decrease of biomass in the leaves of L. hexandra (p>0.05). The highest bioaccumulation coefficients of the leaves for Cr(III) and Cr(VI) were 486.8 and 72.1, respectively. However, L. hexandra had a higher accumulation capacity for Cr(III) than for Cr(VI). At the Cr(III) concentration of 10 mg l(-1) in the culture solution, the concentration of chromium in leaves was 4868 mg kg(-1), while at the same Cr(VI) concentration, the concentration of chromium in leaves was only 597 mg kg(-1). These results confirmed that L. hexandra is a chromium hyperaccumulator which grows rapidly with a great tolerance to Cr and broad ecological amplitude. This species could provide a new plant resource that explores the mechanism of Cr hyperaccumulation, and has potential for usage in the phytoremediation of Cr-contaminated soil and water.
authors.affiliation: Department of Resources and Environmental Engineering, Guilin University of Technology, Jiangan Road 12#, Guilin, Guangxi 541004, PR China.
authors.forename: Xue-Hong
authors.initials: XH
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Huang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Yi-Nian
authors.initials: YN
authors.lastname: Zhu
authors.forename: Dun-Qiu
authors.initials: DQ
authors.lastname: Wang
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D002857:Chromium / Q000378:metabolism*; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002857:Chromium