Bioavailability of Cd in a soil-rice system in China: soil type versus genotype effects
Bioavailability of Cd in a soil-rice system in China: soil type versus genotype effects
复制标题
DOI：
10.1007/s11104-004-2296-7
复制
发表时间：
2005-04-01
期刊：
影响因子：
4.9
通讯作者：
Chen, J
中科院分区：
文献类型：
--
作者：
Li, ZW;Li, LQ;Chen, J
人类通过饮食摄入有毒重金属的风险日益受到关注。在这方面，土壤-作物系统中重金属的生物有效性被认为是控制植物吸收的关键因素，因此是通过食物链转移控制公共卫生风险的关键因素[J.环境。科学。卫生B 34(4)(1999)681]。 2002年，进行了盆栽试验，以阐明土壤类型和水稻基因型对两个对Cd具有不同亲和力的水稻品种对Cd的生物有效性、吸收和分配的相对重要性。结果表明，谷物中镉的总吸收和积累取决于土壤类型和基因型效应。加镉增强了谷物中高镉的吸收和分配。与非 Cd 加标相比，在 Cd 加标方案下，影响 Cd 生物利用度的土壤类型的固有差异不太显着。就土壤磷而言，由于 MgCl2 可提取的镉相对较低，表明镉的生物利用度较低，基因型之间金属亲和力的差异主导了吸收。相反，影响镉生物利用度的土壤类型的固有差异主导了低金属亲和力品种处理的吸收。在所评估的实验条件下，土壤类型和基因型之间的正相互作用导致稻米中Cd含量升高，且Cd值超过中国食品指导标准0.2 mg kg(-1)。结果表明，镉的生物有效性和植物吸收取决于影响镉迁移的土壤化学和物理特性、水稻基因型和土壤污染状况。结果进一步表明，在具有固有镉生物利用度的土壤（如中国江西省的酸性红土）上种植新的高金属亲和力基因型的水稻时应谨慎。
Human exposure to toxic heavy metals via dietary intake is of increasing concern. In this regard, the bioavailability of heavy metals in the soil-crop system is considered to be a key factor controlling plant uptake and, therefore, public health risk through food chain transfer [J. Environ. Sci. Health B 34(4) (1999) 681]. In 2002, a pot experiment was conducted to elucidate the relative significance of soil types and rice genotype on the bioavailability, uptake and partitioning of Cd by two rice cultivars with distinct affinity for Cd. The results indicated that the total uptake of Cd and accumulation in grain was dependent on both soil type and genotype effects. Cd spiking enhanced high Cd uptake and partitioning in grain. Inherent differences in soil type effecting Cd bioavailability were less significant under the Cd spiking regime as compared to non-Cd spiking. In the case of Soil-P, with low Cd bioavailability as indicated by the comparatively lower MgCl2 extractable Cd, differences in metal affinity between genotypes dominated uptake. Conversely, inherent differences in soil type affecting Cd bioavailability dominated uptake in the low metal affinity cultivar treatments. Under the experimental conditions evaluated, the positive interaction between soil type and genotype results in elevated levels of Cd in rice grain with the Cd values exceeding the Chinese food guideline limit of 0.2 mg kg(-1). The results indicated that Cd bioavailability and plant uptake is dependent on soil chemical and physical properties affecting Cd mobility, rice genotype and soil pollution status. The results further suggested that caution should be paid to rice production with the new high metal affinity genotypes on soils with inherent Cd bioavailability as with acidic Red Soils of Jiangxi Provinces, China.