不同水稻品种对重金属的积累特性

采用田间试验法,以南方主要种植的129个水稻品种为研究对象,通过对稻米样品中镉(Cd)、铅(Pb)、铬(Cr)、无机砷(As)和总汞(Hg)重金属含量的测定,分析不同品种和类型的水稻对重金属吸收能力的差异.结果表明,35个早稻糙米Cd含量在0. 35～0. 60 mg·kg~(-1)之间,超标率100%,糙米Pb含量在0. 08～0. 30 mg·kg~(-1)之间,超标率14. 29%; 54个中稻糙米Cd含量在0. 03～0. 45 mg·kg~(-1)之间,超标率33. 33%; 40个晚稻糙米Cd含量在0. 08～0. 20 mg·kg~(-1)之间,均未超过国家标准.早、中、晚稻都表现出三系杂交稻糙米Cd含量高于两系杂交稻,但是差异不明显;早稻三系杂交稻糙米Cr和总Hg含量显著高于两系杂交稻.中稻糙米Cd含量与Pb和总Hg含量间呈显著正相关;与糙米中无机As含量间存在极显著负相关;而与糙米中Cr含量间相关性不明显.总之,水稻对重金属的吸收积累,受遗传背景、品种类型和重金属互作的影响较大.

Accumulation of Heavy Metals in Different Rice Varieties

Field experiments were conducted on the heavy metal contents (Cd, Pb, Cr, inorganic As, and total Hg) of the 129 main cultivated rice varieties in southern China. We analyzed the effects of different varieties and types of rice on the absorption capacities of these heavy metals. The results showed that the Cd content in 35 brown rice of early rice was 0.35-0.60 mg·kg^-1, exceeding the standard rate of 100%. The Pb content in brown rice was 0.08-0.30 mg·kg^-1, exceeding the rate of 14.29%. The Cd content in 54 brown rice of medium rice was 0.03-0.45 mg·kg^-1, exceeding the rate of 33.33%. The Cd content in 40 brown rice of late rice was 0.08-0.20 mg·kg^-1, which did not exceed the national standard. Early, middle, and late rice all showed that the Cd content of three-line hybrid rice was higher than that of two-line hybrid rice, but the difference was not obvious. The contents of Cr and total Hg in brown rice of three-line hybrid rice in early rice were significantly higher than that of two-line hybrid rice. There was a significant positive correlation between Cd content in brown rice and Pb and total Hg content in medium rice, and there was a significant negative correlation between inorganic Cd content and inorganic As content, whereas there was no significant correlation between Cd and Cr content. In short, rice''s absorption and accumulation of heavy metals is greatly affected by genetic background, species types, and heavy metal interactions.