Relationship between paddy soils cadmium pollution and cadmium content in rice.

Cadmium(Cd)is important contaminants in agricultural soil and threatening agriculture and human health.With the development of industry and agriculture,the soil heavy metal cadmium pollution becomes more and more serious.In this study,two high-yielding rice cul-tivars currently used in the local production,Boyou 225,Short glutinous treated with five levels of cadmium in a pot experiment was conduct-ed to study the correlation between Cd accumulation of brown rice and that of paddy soils.Results showed that cadmium was not distributed uniformly in each part of rice plants.Most of the absorbed Cd assembled in the root,the upper,the less.The law of distribution of Cd in differ-ent organs of rice was:root stem rice husk kernels.In rice roots and stems and leaves,cadmium was mainly distributed in the cell wall.Soluble components of cells,cell distribution of low cadmium.That is,F1(Cell wall) F3(soluble part) F2(cell organelles and membrane part).The rice varieties exhibited the genetic character on the Cadmium accumulation.The Cadmium contents of the grains increased with the increasing Cd concentration in soil.According to the state limit of cadmium in rice,the standard(GB 2762-2005),Content≤ 0.2 mg.kg-1.In this study,tropical paddy soil total Cd threshold were Boyou225(Cd total)= 2.0 mg.kg-1;Short glutinous(Cd total)= 3.1 mg.kg-1.There-fore,for reducing the risk of the humanity to heavy metal,the rice varieties with the low capability of accumulating heavy metal in grains could be planted in a polluted soil.