中文摘要：

为了探明Cd胁迫下大豆生长发育及籽粒中Cd的积累和污染状况，采用土壤盆栽实验方法，研究了在两种土壤（红壤和河潮土）中添加不同质量比的Cd对大豆籽粒中N、P、K和zn含量的影响，并对籽粒中Cd的累积量进行了分析。结果表明，两种土壤中添加低质量比Cd（0．25mg／kg）均可促进大豆的生长，高质量比Cd则表现为抑制作用。不同质量比Cd的处理均降低大豆籽粒中N的质量分数，其下降幅度随Cd质量比的升高而增加；低质量比（0．25—050mg／kg）Cd胁迫下，大豆籽粒中Cd-P表现为协同作用，高质量比Cd时则表现为拮抗作用；Cd-K在低质量比Cd胁迫下表现为拮抗作用；Cd-Zn在籽粒中表现为协同作用，叶片中则表现为拮抗作用。将土壤与大豆籽粒中Cd的质量比进行回归分析，表明在红壤中种植大豆，籽粒未受Cd污染（〈0．20mg／kg）的土壤的Cd临界质量比为0157mg／kg，河潮土则为0．769mg／kg。

英文摘要：

The aim of the present paper is to study the effect of different concentrations of Cd on the contents of N, P, K, Zn, Cd in soybean grains that are now cultivated in two kinds of typical Hunan soil, i.e. the red soil and the alluvial soil so as to improve the profitability of reasonable use of the local soil resources slightly polluted by cadmium. The results of our experiments can be shown as follows ： （1） Cd stress at lower concentrations （0.25 mg/kg） helps to increase the height and biomass of soybean plant＇s whereas depressed effects can be found at high Cd coriceutrations with the two kinds of tested soil. （2） Cd treatmeut at different concentrations may lead to the decrease of N content in the soybean grains , Which has been found enhanced with the increase of the Cd concentrations. Furthermore, Cd and Phosphors presence in the grains reveals a synergistic effect at lower Cd concentrations （0.25- 0.50 mg/kg）, and an antagonistic effect at the Cd increased concentrations . At the same time, the presence of Cd and potassium in the soybean grains indicates an antagonistic effect at iow Cd concentrations. While an antagonistic effect is exhibited in the plant leaves, Cd and zinc presence in grains reveals a Synergistic effect. （3） The correlation analysis between Cd concentrations in grains and soils prove that the Cd critical value in the red and alluvial soils is 0.157 mg/kg and 0.769 mg/kg respectively when the Cd content in the grains is below 0.2 mg/kg.