Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Colleges of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China.
Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
Sci Total Environ. 2019 Nov 20;692:1022-1028. doi: 10.1016/j.scitotenv.2019.07.091. Epub 2019 Jul 7.
Contamination of agricultural soil with cadmium (Cd) poses a severe threat to food safety and human health, especially for Cd in rice. It is very important to identify Cd bioaccumulation in rice in order to screen Cd-safe cultivars. In the present study, 183 pairs of rice and soil data collected from Cd-contaminated soil were used to investigate the differences of Cd bioaccumulation in grains among rice cultivars. The results showed that the adverse effect on grain Cd accumulation of japonica was less than that of indica under Cd exposure. The percentage of japonica with grain Cd concentration exceeding 0.2 mg/kg reduced 50.3% compared with indica. Partial correlation analyses suggested that lower pH contributed to Cd accumulation in grains, and a significant increase in grain Cd concentration was observed with increasing soil Cd concentration. The bioaccumulation factors (BCF) of Cd in rice grains could be divided into 5 grades by combining an empirical soil-plant transfer model with species sensitivity distribution (SSD). Grades with lower Cd bioaccumulation (grades 1 and 2) were dominated by japonica, and the intrinsic sensitivity index of Cd-enrichment (k value) and straw to grain transfer factors (TF) increased with ascending grades. Average k value and TF of cultivars in grade 5 were 1.4-7.9 and 1.5-5.7 times higher than those of cultivars in grades 1 to 4, which eventually caused the increase of Cd accumulation in grains. The lower level of Cd absorption and translocation contributed to reducing the bioaccumulation of Cd in rice grains had been proved by the classification of rice on Cd accumulation. Considering the influence of soil properties and intrinsic sensitivity of rice, cultivars with grain Cd bioaccumulation controlled at low levels to safe for human consumption could be identified on Cd-contaminated soils.
农田土壤镉（Cd）污染对食品安全和人类健康构成严重威胁，尤其是对水稻中的 Cd。识别水稻中的 Cd 生物累积对于筛选 Cd 安全品种非常重要。本研究利用采集自 Cd 污染土壤的 183 对水稻和土壤数据，研究了不同品种水稻对籽粒 Cd 累积的差异。结果表明，Cd 暴露下，粳稻比籼稻对籽粒 Cd 累积的不良影响更小。与籼稻相比，籽粒 Cd 浓度超过 0.2mg/kg 的粳稻比例降低了 50.3%。偏相关分析表明，较低的 pH 值有助于 Cd 在籽粒中的累积，而随着土壤 Cd 浓度的增加，籽粒 Cd 浓度显著增加。将经验土壤-植物转移模型与物种敏感性分布（SSD）相结合，可将水稻籽粒中 Cd 的生物累积因子（BCF）分为 5 个等级。低 Cd 生物累积（等级 1 和 2）的品种以粳稻为主，Cd 富集的固有敏感性指数（k 值）和秸秆向籽粒的转移因子（TF）随等级升高而增加。等级 5 中品种的平均 k 值和 TF 比等级 1 到 4 中的品种高 1.4-7.9 倍和 1.5-5.7 倍，这最终导致了籽粒中 Cd 累积的增加。通过对 Cd 累积的水稻品种进行分类，证明了降低 Cd 吸收和转运水平有助于减少水稻籽粒中 Cd 的生物累积。考虑到土壤性质和水稻内在敏感性的影响，可以在 Cd 污染土壤上识别出籽粒 Cd 生物累积水平较低且对人体安全的品种。
