低铅污染条件下不同类型水稻品种对铅的响应

Responses of Rice Cultivars to Low-level Pb Pollution

以35个水稻品种为材料,采用人工污染的方法,研究了不同类型品种对被污染土壤中铅(Pb)的吸收特性及Pb在不同器官的积累。结果表明:在低Pb污染处理(土壤中Pb浓度为149.1 mg/kg)下,不同类型水稻品种、不同器官中Pb的积累量有明显差异,稻谷和精米中均以常规籼稻的积累量最多,常规粳稻积累量最少,杂交稻介于两者之间。低Pb污染和对照条件下,土壤中的Pb较多地在茎叶中积累,而由茎叶向稻谷或精米中运输的比例很低。土壤受低浓度Pb污染时,水稻籽粒中Pb的积累量并未显著高于对照。筛选结果显示,南粳41、南粳40精米中Pb含量达到绿色食品标准;华粳3号等5个品种达到无公害大米标准。

Pb absorption characteristics of different organs of 35 rice cultivars were investigated by adding Pb to the soil. Pb was accumulated the most in the grains and milled rice of conventional indica and the least in those of conventional japonica. The Pb concentration in the grains and milled rice of hybrid plants was between above two types of rice. Compared to massive Pb accumulation in the stem and leaves of rice plants, the concentrations of Pb in rice grains were lower in both the low-level Pb pollution （149. 1 mg/kg） treatment and the control（ No Pb）. There was no obvious difference between Pb concentration in rice grains under low-level Pb pollution and the control. Some rice cultivars, Nanjing 41 and Nanjing 40, met the green food rice standard, and Huajing 3 ,which met the clean food rice standard,were selected out.