材料期刊网

采用水培试验,研究Zn缺乏和正常条件下,喷施不同浓度的ZnSO4和ZnNa2EDTA对两种油菜地上部生物量和Cd、Zn、Fe、Mn、Cu等元素含量的影响,并通过设置喷施Na2EDTA处理和分析Cd在油菜体内的累积分配规律来揭示喷施Zn肥降低油菜Cd含量的作用机理.结果表明,正常Zn营养下油菜地上部生物量显著高于Zn缺乏条件下,不同Zn营养条件下喷施Zn肥对油菜地上部生物量都没有显著影响.正常Zn营养下油菜地上部Cd含量极显著低于Zn缺乏条件下;正常Zn营养下喷施ZnSO4使得普通油菜寒绿的地上部Cd含量显著低于对照处理,降幅为27.22％;Zn缺乏时喷施低浓度和高浓度ZnNa2EDTA使得Cd低积累油菜华骏的地上部Cd含量显著降低,与对照相比分别减少28.70％和26.94％,喷施ZnNa2EDTA降低油菜地上部Cd含量的作用与EDTA成分没有密切关系;喷施Zn肥主要通过抑制根部Cd吸收来降低油菜的地上部Cd含量,正常Zn营养下油菜地上部Zn含量极显著高于Zn缺乏条件下;喷施Zn肥显著提高油菜地上部和根部Zn含量.正常Zn营养下油菜地上部Fe含量极显著低于Zn缺乏条件下,Zn营养条件对油菜地上部Mn和Cu含量没有显著影响;不同Zn营养条件下喷施Zn肥可使油菜地上部Fe、Mn、Cu含量显著升高或降低,但是并没有显著影响油菜微量元素的营养平衡.

A solution-culture experiment was conducted to investigate the effect of foliar application of ZnSO4 and ZnNa2EDTA on the shoot biomass of two cultivars of pakchoi,as well as the influence on the concentrations of cadmium (Cd),zinc (Zn),iron (Fe),manganese (Mn) and copper (Cu) in pakchoi under low and sufficient Zn conditions.Moreover,the mechanism of minimizing Cd absorption in pakchoi by foliar Zn fertilizer was elucidated through arranging the treatments of foliar applied Na2EDTA and analyses of Cd uptake and transloacting in tested pakchoi cultivars.Results show that the shoot biomass of the tested pakchoi cultivars under sufficient Zn condition was significantly higher than that under low Zn.Meanwhile,foliar Zn application had nosignificant effect on shoot biomass under both low and sufficient Zn levels.The Cd contents in the tested pakchoi cultivars under sufficient Zn condition were significantly lower than those under low Zn condition.Supplied with sufficient Zn,foliar application of ZnSO4 significantly decreased shoot Cd concentrations of the common cultivar Hanlv,with a 27.22％ reduction compared to the control.Under low Zn condition,foliar application of low and high dosage of ZnNa2 EDTA significantly reduced shoot Cd concentrations in the low cadmium accumulating cultivar Huajun,with reductions of 28.70％ and 26.94％ respectively compared to the control.EDTA could not be germane to the decrease in shoot Cd concentration under foliar ZnNa2EDTA treatments.The inhibition of Cd uptake by root resulted in decrease in shoot Cd concentrations under foliar Zn treatments.Tested pakchoi cultivars under sufficient Zn condition had a significantly higher mean shoot Zn concentration than those under low Zn,and foliar applied Zn significantly increased the Zn concentrations in shoot and root of pakchoi.The concentrations of Fe in tested pakchoi cultivars under sufficient Zn condition significantly decreased in contrast to those under low Zn condition,but there were not significant effects of Zn nutrition status on shoot Mn and Cu concentrations.Fe,Mn and Cu concentrations in shoots were significantly increased or decreased after applying different foliar Zn,but they were still in the normal range required for plant growth.