Cd Accumulation in Japonica Rice Relative to Growth Type

The experiment was set to investigate accumulation of cadmium in 56 varieties of Japonica rice of 5 different growth types growing in cadmium-polluted farmlands. The 5 growth types include early-maturity (125–135 d), mid-maturity (136–145 d) and late-maturity (146–155 d) mid-japonica rice and early-maturity (156–165 d) and mid-maturity (166–175 d) late-japonica rice. Results show that Cd concentration in grain of the 56 varieties of rice varied from variety to variety sharply in the range of 0.014-0.054 mg•kg^-1 (P＜0.05).For Cd concentration in grains among the 56 varieties, ELTO was the highest and Yangjing 687, Siyang 1382, Guanglingxiangjing and Wuxiangjing 9 were lower. For the 5 growth types, the type of early-maturity mid-japonica rice was higher and the type of mid-maturity mid-japonica rice was lower in Cd concentration, being 0.024 and 0.020 mg•kg^-1, respectively. The difference between the types of japonica rice was not significant in Cd accumulation coefficient, but significant in Cd transfer coefficient.