叶面施加纳米氧化锌对木槿生长及生理特性的影响

Effects of Foliar Application of Zinc Oxide Nanoparticles in Hibiscus syriacus

【目的】研究叶面施加纳米氧化锌(ZnO NPs)对木槿生长与生理指标的影响,探讨纳米氧化锌对园林植物的生长调节作用。【方法】以木槿实生幼苗为材料,叶面施加不同粒径、不同浓度的ZnO NPs以及ZnSO_(4)·7H_(2)O溶液,比较不同处理下木槿的生长、生理指标和叶片锌含量的差异。【结果】(1)三种粒径的ZnO NPs在浓度为50 mg/L时对木槿生长生理特性的促进作用均强于ZnSO_(4),其中50 nm ZnO NPs处理下木槿幼苗株高、叶绿素含量、SOD活性、可溶性蛋白含量均显著增加(P<0.05)。(2)三种粒径的ZnO NPs浓度为100 mg/L时,均对木槿的生长产生抑制作用,并且50 nm ZnO NPs抑制作用最显著。(3)叶片的锌含量随ZnO NPs浓度上升而增加,并且粒径越小上升幅度越大。(4)通过主成分分析进行综合得分排序,三种粒径的ZnO NPs对木槿生长生理特性促进作用以及叶片锌含量增加的综合能力排序为50 nm>30 nm>90 nm。【结论】叶面施加ZnO NPs对木槿生长有促进作用,但其促进程度与ZnO NPs粒径大小及浓度有关。ZnSO_(4)处理对木槿生长的促进作用随着施加次数增多而减弱,而ZnO NPs对木槿的影响是持续性的并且施加ZnO NPs对木槿生长的促进作用比ZnSO_(4)效果更加显著。

【Objective】It is to investigate the effects of foliar application of zinc oxide nanoparticles(ZnO NPs)on the growth and physiological indexes of Hibiscus syriacus,and to explore the growth regulating effects of ZnO NPs on ornamental plants.【Methods】Foliar application of ZnO NPs with different particle sizes and concentrations,as well as ZnSO_(4)·7H_(2)O solution were used to compare the differences in growth,physiological indexes and leaf zinc content of Hibiscus syriacus under different treatments.【Results】(1)All three sizes of ZnO NPs had a stronger effect on the growth and physiological characteristics of Hibiscus syriacus than ZnSO_(4)at the concentration of 50 mg/L.The height,chlorophyll content,SOD activity and soluble protein content of seedlings were significantly increased under 50 nm ZnO NPs treatment.(2)All the three particle size concentrations of 100 mg/L inhibited the growth of seedlings,and the 50 nm ZnO NPs had the most significant inhibitory effect.(3)The Zn content of leaves increased with the increase of ZnO NPs concentration,and the smaller the particle size,the greater the increase.(4)The combined score ranking by principal component analysis showed that the combined ability of the three sizes of ZnO NPs to promote the physiological properties of Hibiscus syriacus growth and increase the leaf zinc content was ranked as 50 nm>30 nm>90 nm.【Conclusion】The foliar application of ZnO NPs promoted the growth of Hibiscus syriacus,but the promotion was dependent on the size and concentration of ZnO NPs.The growth of Hibiscus syriacus was slightly improved by ZnSO_(4)treatment,but the promotion effect decreased with the increase of application times.The effect of ZnO NPs on Hibiscus syriacus was continuous and the promotion effect of ZnO NPs was more significant than that of ZnSO_(4).