ABSTRACT

Low transfer of radioactive cesium (radiocesium) from soil to grains of agricultural crops is desirable to ensure food safety for humans and animals. Although the transfer of radiocesium from soil to grains is higher in upland crops such as soybean (Glycine max L.) than in paddy rice (Oryza sativa L.), little information related to the specific difference in radiocesium accumulation among leguminous crops is available, or for the relation between soil conditions and radiocesium accumulation in leguminous crops. This study compared the pattern of radiocesium transfer from soil to grains between peanut (Arachis hypogaea L.) and soybean to elucidate the diversity of radiocesium accumulation in leguminous crops growing with different potassium levels in soil. Pot and field experiments with radiocesium-contaminated soil showed that the radiocesium concentration in grains was lower in peanut than in soybean plants. For peanut, radiocesium absorption was mainly from roots instead of gynophores and fruits formed in the soil. Radiocesium absorption and translocation from roots to shoots were lower in peanut than in soybean plants. Among shoot parts, radiocesium transfers from stems to leaves, shells, and grains were lower in peanut than in soybean plants. Potassium application to the soil decreased the radiocesium transfer from soil to grains in both crops. The radiocesium accumulation was lower in peanut than in soybean under both potassium applied and non-applied conditions. These results underscored the variation in radiocesium transfer from soil to grains in leguminous crops, and demonstrated that peanut plants had lower potential of radiocesium accumulation than soybean plants.

摘要

放射性铯（radiocesium）从土壤到农作物谷物的低转移对于确保人类和动物的食品安全是可取的。尽管在大豆（Glycine max L. ）等旱田作物中放射性铯从土壤转移到谷物中比在水稻（Oryza sativa L. ）中更高，但关于豆科作物之间放射性铯积累的具体差异的信息很少，或土壤条件与豆科作物放射性铯积累之间的关系。本研究比较了花生 ( Arachis hypogaeaL.) 和大豆来阐明土壤中不同钾含量的豆科作物中放射性铯积累的多样性。放射性铯污染土壤的盆栽和田间试验表明，花生谷物中的放射性铯浓度低于大豆植物。对于花生，放射性铯的吸收主要来自根部，而不是在土壤中形成的雌蕊和果实。花生对放射性铯的吸收和从根到芽的转运低于大豆植物。在芽部分，从茎到叶、壳和籽粒的放射性铯在花生中的转移低于大豆植物。在两种作物中，向土壤施用钾肥减少了放射性铯从土壤向谷物的转移。在施钾和不施钾条件下，花生的放射性铯积累量均低于大豆。这些结果强调了豆科作物中放射性铯从土壤转移到谷物的变化，并证明花生植物的放射性铯积累潜力低于大豆植物。