摘要
A pot experiment was conducted with two rice genotypes having different Cd concentrationsin their grains to study the effect of soil Cd level on biomass, Cd and Fe, Zn, Cr andPb accumulation in different plant parts. Cd was added into soil to form 4 levels, i.e.,0, 0.5, 2.5 and 12.5mgkg-1, respectively. The results showed that the Cd-induced reductionin biomass accumulation varied in both genotypes and growth stages. The Cd-inducedreduction in biomass became less with the progress of growth, and Xiushui63, a genotypewith relatively higher grain Cd concentration, was more severely inhibited than Xiushui217,a relatively lower Cd concentration. Both Cd concentration and accumulation in thevarious plant parts increased substantially with the increase of Cd levels. The differencebetween two genotypes in Cd concentration and accumulation became more pronounced withincreased Cd level as well as prolonged duration of exposure. Xuishui63 had much greaterCd accumulation than Xiushui217, in particular at late growth stage. Xuishui63 had aremarkably higher Cd translocation of roots to shoots than Xiushui217 in all Cd levels.The effect of Cd addition on four microelement concentrations in straw and milled ricealso varied in genotypes and Cd levels. Without Cd addition, Xiushui63 was significantlylower than Xiushui217 in the concentrations of all four elements in straw, while the casewas just opposite in milled rice. Zn, Fe and Pb concentrations decreased in milled ricewith the increase of Cd level, although the reduction extent differed in two genotypes.The results indicated that Cd concentration in rice grain is primarily dependent on theshoot Cd concentration, which is in turn mainly determined by Cd translocation from rootsto shoots.
A pot experiment was conducted with two rice genotypes having different Cd concentrationsin their grains to study the effect of soil Cd level on biomass, Cd and Fe, Zn, Cr andPb accumulation in different plant parts. Cd was added into soil to form 4 levels, i.e.,0, 0.5, 2.5 and 12.5mgkg-1, respectively. The results showed that the Cd-induced reductionin biomass accumulation varied in both genotypes and growth stages. The Cd-inducedreduction in biomass became less with the progress of growth, and Xiushui63, a genotypewith relatively higher grain Cd concentration, was more severely inhibited than Xiushui217,a relatively lower Cd concentration. Both Cd concentration and accumulation in thevarious plant parts increased substantially with the increase of Cd levels. The differencebetween two genotypes in Cd concentration and accumulation became more pronounced withincreased Cd level as well as prolonged duration of exposure. Xuishui63 had much greaterCd accumulation than Xiushui217, in particular at late growth stage. Xuishui63 had aremarkably higher Cd translocation of roots to shoots than Xiushui217 in all Cd levels.The effect of Cd addition on four microelement concentrations in straw and milled ricealso varied in genotypes and Cd levels. Without Cd addition, Xiushui63 was significantlylower than Xiushui217 in the concentrations of all four elements in straw, while the casewas just opposite in milled rice. Zn, Fe and Pb concentrations decreased in milled ricewith the increase of Cd level, although the reduction extent differed in two genotypes.The results indicated that Cd concentration in rice grain is primarily dependent on theshoot Cd concentration, which is in turn mainly determined by Cd translocation from rootsto shoots.
基金
Zhejiang Provincial Natural Science Foundation(M303510)
British Council(SHA/992/310),Science and Technology Department of Zhejiang Province(2003C32049)
Science and Technology Bureau of Jiaxing,Zhej iang Province,China(0110,20021034)for their financial supports.
