不同陪伴阴离子条件下Zn对玉米吸收积累Cd的影响

Influence of Zinc on Uptake of Cadmium by Maize Plants(Zea mays)Under Different Accompanying Anions

采用盆栽试验方法研究了不同陪伴阴离子条件下,土壤不同Zn含量对2个品种玉米吸收Cd、Zn的影响。不同阴离子NO-3、Cl-、SO42-以Zn(NO3)2,ZnCl2和ZnSO43种不同Zn化合物形式添加,添加Zn浓度设0、80、160和240mg·kg-14个水平,土壤Cd浓度为10mg·kg-1。结果表明,土壤中Zn添加促进了玉米生物量,其中NO-3陪伴下增加幅度最大。与对照相比,不论何种阴离子陪伴下,土壤中Zn的添加都明显降低了2个品种玉米地上部分的Cd含量(P<0.001),最小Cd含量出现在Zn80mg·kg-1或Zn160mg·kg-1处理。3种阴离子相比,NO-3比SO24-和Cl-降低幅度更为明显(P<0.001)。不同阴离子陪伴下2个品种玉米体内Cd浓度大小分别为(吉单209)SO42->Cl->NO-3,(长单374)Cl->SO24->NO-3。SO24-和Cl-处理下Cd浓度并未表现出显著差异。与地上部相反,Cl-陪伴时根系Cd浓度较低,而SO42-陪伴下Cd浓度最高。Cl-利于玉米根系对Zn的吸收及向地上部分的转移。

A pot experiment was conducted to investigate the effects of zinc with different accompanying anions on uptake of cadmium and zinc by two cultivars of maize plant （Zea mays）： Jidan209 and Changdan374, extensively grown in Northeast China. Different accompanying anions NO3^-, Cl^- and SO4^2- were added to soil as Zn（NO3）2,ZnCl2 and ZnSO4 at four zinc levels： 0, 80, 160 and 240 mg·kg^-1 soil. Cd（NO3）2 was added at 10 mg·kg^-1 soil in all the treatments. The results showed that the biomass of maize plants increased by adding zinc to soil irrespective of the different accompanying anions, and increased much more by zinc nitrate than the others. Zinc addition with all the three anions decreased Cd concentration in shoots in comparison with the treatment without Zn （P〈0.001）. However, the lowest Cd concentrations in shoots were not presented in Zn 240 mg ·kg^-1 treatment but in 80 mg ·kg^-1 or 160 mg·kg^-1 treatment due to the higher Zn concentrations applied in this experiment. There existed significant differences for Cd concentrations of maize plants treated with different anions and the maize with nitrate had the least value （P〈0.001）. The order of average Cd concentrations in shoots with different anions was SO4^2- 〉Cl^-〉 NO3^- for Jidan209 and Cl^- 〉 SO4^2- 〉NO3^- for Changdan374, respectively. There was no significant difference observed between the treatments of SO4^2- and Cl^- . Unlike in shoots, the Cd concentrations in roots added with Cl^- was the lowest instead and that with SO4^2- was the highest. Zinc accompanied with Cl^- was easier to uptake by roots and transfer to shoots.