Abstract: 【Objective】It is important to remediate Cd-polluted soils and select the cultivars with high Cd accumulation ability. The characteristics of cadmium-accumulated rice cultivars with high cadmium accumulation, and the purification ability to Cd-polluted soil were studied to provide a theoretical basis for restoration of Cd-polluted soil.【Method】Two Cd high-accumulation cultivars (Lu17-T2171 and Wujin4B) were screened earlier, with common variety Luhui17 as contrast. A pot culture experiment was carried out in a net room on the farm of Sichuan Agricultural University, Sichuan province, China in 2010, including soil culture experiment with Cd treatments of 0 mg•kg-1, 2 mg•kg-1, 10 mg•kg-1, and 50 mg•kg-1. The differences between cultivars in purification ability of rice to the soil Cd were discussed.【Result】As the concentration of Cd increased, the biomass of Cd high-accumulation cultivars was also increased. Biomass of Lu17-T2171 increased by 33.96% and 19.51%, respectively, at tillering stage and flowering stage with Cd50, compared with Cd0; while that Wujin4B increased by 54.71% and 15.22%, respectively. High-accumulation cultivars with stronger absorptive capacity to Cd at tillering stage. Under the condition of Cd50, Cd contents in shoot and root of Lu17-T2171 reached 87.24 mg•kg-1 and 400.59 mg•kg-1, respectively, which were 2.38 and 2.86 times higher than Luhui17, while those of Wujin4B reached 102.26 mg•kg-1 and 384.77 mg•kg-1, respectively, 2.79 and 2.86 times higher than Luhui17. Enrichment factor of both rice cultivars decreased as Cd concentration increase, moreover, the high-accumulation cultivars were apparently higher than common cultivars. High-accumulation cultivars with stronger ability to accumulate cadmium at flowering stage. Under the condition of Cd50, Cd accumulations in shoot and root of Lu17-T2171 reached 1 847.20 μg/pot and 892.06 μg/pot, respectively, 2.91 and 2.74 times higher than Luhui17, while those of Wujin4B reached 1 895.37 μg/pot and 783.42 μg/pot, respectively, 2.98 and 2.41 times higher than Luhui17. Moreover, the migration rate of high-accumulation cultivars at flowering stage was obviously higher than that of common cultivars. The purification rate in plant and shoot of high-accumulation cultivars was apparently higher than that in common cultivars. Under the condition of Cd50, the purification rate in plant and shoot of Lu17-T2171 reached 5.07% and 3.42% at flowering stage, 2.86 and 2.90 times higher than Luhui17, while those of Wujin4B reached 4.96% and 3.51%, 2.79 and 2.98 times higher than Luhui17. 【Conclusion】 Cd high-accumulation rice cultivars showed a high absorptive capacity and accumulation ability to Cd at tillering stage and flowering stage. Thus, it can be taken as potential restoration material for Cd-polluted farmlands.

Key words: rice , Cd , high accumulation , phytoremediation