叶面喷施不同浓度锌对水稻锌镉积累的影响

Effect of foliar spraying zinc on the accumulation of zinc and cadmium in rice

采用田间小区试验研究在水稻灌浆初期叶面喷施不同浓度锌(1~5 g·L-1Zn SO4)对水稻(株两优189)产量、各器官镉锌含量和镉转运的影响。结果表明:叶面喷施1~5 g·L-1Zn SO4对水稻产量无显著影响(P>0.05)。叶面喷施1~5 g·L-1Zn SO4水稻各器官Cd含量降低、而Zn含量提高。糙米Cd含量降低9.0%~47.8%,Zn含量提高31.7%~55.6%。喷锌后根到第一节Cd转运系数(TF第一节/根)、旗叶向第一节Cd转运系数(TF第一节/旗叶)和穗轴到糙米Cd转运系数(TF糙米/穗轴)分别降低5.8%~43.7%、1.0%~30.3%和4.7%~26.7%。糙米Cd含量与TF第一节/根、TF糙米/穗轴和根Cd含量呈极显著正相关关系(P<0.01)。研究结果表明,叶面喷锌降低糙米Cd含量主要是由于抑制根Cd吸收和降低根和旗叶向第一节及穗轴向糙米的转运引起的。喷施3~5 g·L-1Zn SO4显著降低糙米Cd含量,是叶面调控稻米Cd含量的适宜用量。

In this study,a field plot experiment was conducted to study the effects of different concentrations of zinc(1~5 g·L-1 ZnSO4)on yield,cadmium-zinc concentration and cadmium transport of rice(Zhuliangyou 189)at early grain filling stage of rice.The results showed that foliar spraying 1~5 g·L-1 ZnSO4 had no significant effect on rice yield(P>0.05).The concentrations of Cd decreased and the Zn concentrations increased in the various organs of rice plants sprayed with 1~5 g·L^-1 ZnSO4.The concentrations of Cd in brown rice were decreased by 9.0%~47.8%,and the concentrations of Zn increased by 31.7%~55.6%with foliar application 1~5 g·L^-1 ZnSO4.After foliar application with 1~5 g·L^-1 ZnSO4,translocation factors(TFs)of Cd from roots to the first nodes(TFs(First nodes/Roots)),from flag leaves to the first node(TFs(Firstnodes/Falg leaves)),and from rachises to brown rice(TFs(Brown rice/Rachises))was decreased by 5.8%to 43.7%,1.0%to 30.3%,and 4.7%to 26.7%,respectively.There was a significant positive correlation between Cd concentration in brown rice and TFs(First nodes/Roots),TFs(Brown rice/Rachises),and root Cd concentrations(P<0.01).These results indicate that foliar applied Zn reduced Cd concentrations in brown rice by inhibiting the uptake of Cd by root and translocation of Cd from root and flag leaves to the first nodes,and from rachises to brown rice.Foliar spraying 3~5g·L^-1 ZnSO4 significantly reduced the Cd concentrations of brown rice,which was the appropriate amount of foliar application of Zn to reduce Cd concentration in brown rice.