中文摘要：

以籽粒Cd富集能力不同的两个基因型水稻为材料，通过盆栽试验研究水稻地上部对Cd的积累特征及其产地土壤Cd临界值。结果表明，土壤Cd添加量为0～1．5mg·kg-1时，其对水稻生长和产量无明显抑制效应，两个基因型水稻的生长和Cd富集能力也无显著差异。水稻地上部对Cd的富集量由高到低依次为茎秆、叶、糙米和稻壳，但土壤Cd全量、CaCl2提取态Cd与糙米Cd含量之间均呈显著正相关。依据GB2762--2005《食品中污染物限量》中大米Cd限量值及糙米的Cd累积特征，反推得到天津潮土（pH值为7．71）Cd全量临界值为2．1mg·kg-1，CaCl2提取态Cd临界值为5．7μg·kg-1（基于Cd高积累型水稻）。该研究结果可为GB15618--1995《土壤环境质量标准》的修订及农产品产地适宜性评价提供基础数据。

英文摘要：

A pot experiment was conducted to investigate Cd accumulation in two genotypes of rice cuhivars, different in Cd enriching capacity and to derive total and available Cd fraction based soil Cd threshold value in rice producing area. Results show that Cd, at 0 - 1.5 mg · kg - 1 had no significant inhibitive effect on growth or yield of rice. Cd accumulation in rice, in general, increased with increasing soil Cd concentration, and Cd concentration in different rice organs varied, showing an discending order of stalk, leaf, brown rice, and husk. However, no significant difference was found between the two rice genotypes in plant growth and Cd accumulation capacity in the experiment. Cd in brown rice was significantly related to soil total Cd and CaCl2 extractable Cd. Based on the national food hygienic standards （ GB 2762 - 2005 ） and Cd accumulation characteristics of the two rice genotypes, Cd threshold value of the Fluvo-aquic soils （pH 7.71 ） in Tianjin was derived to be 2. 1 mg · kg-1 and CaCl2 extractable Cd threshold value of the soil 5.7 μg·kg-1. The findings of this study can be used as scientific reference for revision of the national standards for soil environment quality and for suitability assessment of soils for rice production.