Abstract:Aims Our objective was to compare growth responses to soil Cd, as well as Cd uptake and accumulation in two ecotypes of Sedum alfredii. Methods In a pot experiment, we planted one mining ecotype of S. alfredii and one non-mining ecotype in eight soils with different Cd levels (control, 12.5, 25 , 50, 100, 200, 300, 400 mg•kg-1) for two successive croppings. Important findings The mining ecotype of S. alfredii grew healthy at all Cd supply levels. Its Cd concentrations in shoots and roots linearly increased with increasing soil Cd levels and reached a maximum of approximately 2 900 mg•kg-1 (DW) and 500 mg•kg-1 at 400 mg•kg-1 treatment, respectively. Its Cd concentration in shoots was far higher than roots. In contrast, the growth of the non-mining ecotype was severely inhibited by soil Cd supply, as its shoot and root biomass significantly decreased compared with the control treatment. Cd concentrations in shoots an d roots of the non-mining ecotype also increased with increasing soil Cd levels, but its Cd concentration in roots was higher than in shoots. At low soil Cd levels (≤50 mg•kg-1), Cd concentration in roots of the mining ecotype was higher than the non-mining ecotype, while there were no significant differences between the two ecotypes at high Cd levels (100 and 200 mg•kg-1). Increasing soil Cd levels from 0 to 400 mg•kg-1 enhanced Cd concentration in shoots of the two ecotypes, and Cd concentration in shoots of the mining ecotype was always far higher than the non-mining ecotype at all Cd supply levels. These results indicate that the mining ecotype of S. alfredii has an extraordinary ability to tolerate and uptake Cd from soil and is proved to be a Cd hyper-accumulator.