Abstract: A pot experiment was carried out in mildly and severely cadmiumpolluted soil with 48 rice varieties suitable for planting in Hunan. Based on the analysis of grain yield, the enrichment coefficient of each organ, the transfer coefficient and purification ability of plants, the effects of different cadmium pollution levels on the cadmium accumulation, translocation and purification efficiency of rice were studied. The results showed that the cadmium content and grain yield of brown rice were 0.010-0.048 mg·kg^-1 and 96.63-152.55 g·pot^-1 for mildly cadmium-polluted soil, and 0.105-0.476 mg·kg^-1 and 101.10-165.12 g·pot^-1 for severely cadmium-polluted soil, respectively. Severely cadmiumpolluted soil significantly increased cadmium content in brown rice, but had little effect on grain yield. There was no significant correlation between yield and cadmium enrichment efficiency of brown rice in mildly and severely cadmium polluted soil. Based on the analysis of the yield and the concentration of cadmium in brown rice, all the varieties were divided into low cadmium-low yield group and low cadmium-high yield group under mildly cadmium-polluted soil, and high cadmium low yield group and high cadmium high yield group in severely cadmium polluted soil. The cadmium accumulation and translocation efficiency in organs of rice were in the order of brown rice<leaf<stem<root and soil-root>stem-leaf>stem-brown rice>root-stem, respectively. Soil cadmium was transported to roots and enriched in roots. The cadmium accumulation and translocation efficiency of rice were less affected by yield factors, but greatly affected by soil cadmium enrichment. Severely cadmium polluted soil significantly enhanced the cadmium enrichment of each organ and the translocation efficiency of root brown rice, compared to mildly cadmium polluted soil. The purification efficiency of rice roots was much higher than that of the aboveground parts.

Key words: tea-applied chrysanthemum, planting date, pinching, new varieties (line), yield.