Abstract: Sedum alfredii is a newly reported zinc (Zn) and cadmium (Cd) hyperaccumulator native to China. In this study, four populations of S. alfredii were collected from Yejiwei (YJW), Jinchuantang (JCT) and Qiaokou (QK) lead (Pb)/Zn mines located in Hunan Province as well as Quzhou (QZ) Pb/Zn mine located in Zhejiang Province for exploring the intraspecies difference of this plant in metal accumulation. Although they grew in the Pb/Zn spoils with relatively similar levels of Zn, Cd and Pb, remarkable differences among the four populations in tissue heavy metal concentrations were observed. The shoot Zn concentration of QZ population (11,116 mg kg-1) was highest and nearly 5 times higher than that of JCT population (1,930 mg kg-1). Furthermore, the shoot Cd concentration observed in QZ population (1,090 mg kg-1) was also highest and 144 times higher than that found in JCT population (7.5 mg kg-1). As to Pb concentrations in shoot of different populations, a 4-fold difference between the highest and the lowest was also found. Such difference on metal accumulation was population specific and was might be significantly explained by differences in the soil properties such as pH, organic matter (OM), and electrical conductivity (EC). Taking biomass and metal concentration in plants into consideration, QZ, YJW and QK populations had high potential in Zn phytoremediation, QZ population had the highest potential in Cd phytoremediation, and QK population was most useful in Pb phytoremediation.

Key words: Sedum alfredii, heavy metal, hyperaccumulation, phytoremediation, population