不同水稻品种对镉的积累及其动态分布

Accumulation Characteristic and Dynamic Distribution of Cd in Different Genotypes of Rice(Oryza sativa L.)

选取10个水稻品种进行大田试验,研究了不同水稻品种对Cd的积累特征及其动态分布规律。结果表明:成熟期水稻不同部位Cd积累规律为根系>茎叶>稻壳>糙米。常规稻根系Cd含量在幼苗期最低,分蘖期最高,而杂交稻生长周期小于120d的水稻根系Cd含量最大值出现在分蘖期,生长周期大于120d的水稻根系Cd含量最大值出现在成熟期。水稻茎和叶中Cd的含量呈先升高后降低再升高的趋势,在成熟期达到最高值。不同品种水稻糙米内Cd的含量范围为0.21～1.53mg·kg-1,Cd含量相对较低的常规稻和杂交稻分别为湘早籼42和T优705,均接近或超过国家粮食卫生标准限值(0.2mg·kg-1)。

Field experiment was conducted to investigate the accumulation characteristics and dynamic distribution of Cd in ten genotypes of rice. The results showed that the distribution of Cd in various rice plant parts was in the order：root〉leaf and stem 〉husk〉brown rice. The concentrations of Cd in roots of conventional rice were the lowest at seeding stage, and the highest at tillering stage, while of Cd in root of hybrid rice with growth cycle less than 120 days and over 120 days were the highest at tillering stage and mature stage, respectively. The tendency of Cd concentration in leaf and shoot of rice increased firstly, decreased, and then increased to a peak at mature stage. In the present study, the contents of Cd in brown rice samples（Xiang Zao-xian 42 and T-you 705） were relatively low among conventional rice and hybrid rice, while the ranges of concentrations of Cd in brown rice（0.21-1.53 mg·kg^-1） were closed to, even beyond the limit of the food health standard（0.2 mg·kg^-1）.