Pot experiment was conducted to investigate the effects of different concentration of silicon (0,1.5, 2. 0,2. 5 mmol/kg) treatment on biomass,Cd and Zn content in shoots and roots of rice plants under the combined Cd and Zn stress. The results showed that,Si application significantly increased the biomass of rice plants under single and combined treatment of Cd and Zn, 1. 5 mmol/kg had the best effect. The content of Cd and Zn in plant was significantly decreased due to silicon treatment, but there was difference between varieties and treatments. For variety Feng-hua-zhan,2. 0 -2. 5 mmol/kg silicon treatment had the largest reduction of Cd content in plant,for Zn content, it was 1.5 mmol/kg silicon treatment. For variety Hua-hang-si-miao,2. 0 -2.5 mmol/kg silicon treatment had the largest reduction of Cd and Zn content in rice shoots, however, it was 1.5 mmol/kg silicon treatment for roots. There was interaction in metal absorption between Cd and Zn treatments. Zn content of plant roots in combined Cd and Zn treatments was higher than that in single Zn treatment for both varieties; however, Cd and Zn content in shoots in combined Cd and Zn treatments were lower than that in single Cd and Zn treatment only for Huang-hang-si-miao variety.%通过盆栽试验研究了镉(Cd)、锌(Zn)复合胁迫下,外源施加不同浓度的硅(0,1.5,2.0,2.5 mmoL/kg)对水稻幼苗生物量及地上部和地下部Cd和Zn含量的影响.结果表明,无论是在Cd和Zn单一或者复合污染条件下,不同浓度的硅处理均能显著提高水稻幼苗地上部和根系的生物量,其中以硅浓度为1.5 mmol/kg时效果最好.硅处理能显著降低植株重金属Cd和Zn的含量,但不同品种和不同处理的效果存在差异.对于品种丰华占来说,降低幼苗Cd和Zn含量幅度最大的硅浓度分别为2.0 ～ 2.5 mmol/kg及1.5 mmol/kg；华航丝苗品种则在硅浓度为2.5 mmol/kg和2.0 mmol/kg时,地上部Cd和Zn含量降低最明显,地下部则以硅浓度为1.5 mmol/kg时效果最好.Cd和Zn复合胁迫对水稻植株重金属含量的影响具有一定的交互作用,但品种间存在差异.对于地下部Zn含量,两个品种均为复合污染大于单一污染；地上部Zn和Cd含量,华航丝苗均为复合污染小于单一污染.
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