Seasonal variation of microelement contents in leaves of <Emphasis Type="Italic">Cyclocarea paliurus</Emphasis> among the provenances

Cyclocarya paliurus as a multiple function plant can accumulate biologically important microelement elements. To reveal the variation of selected microelement concentrations in leaves of C. paliurus provenances during the growing season, 12 C. paliurus provenances in the field trial were sampled five times at approximately 1-month intervals. The method of inductively coupled plasma optical emission spectrometer (ICP-OES) was employed to determinate average concentrations of Fe, Mn, Zn, Cu and Se in leaves of 12 C. paliurus provenances. The results show that on average, the concentrations of five microelement in the leaves follows an order of Fe > Mn > Zn > Cu > Se. Variance analysis shows that there are significant differences in Fe, Mn and Zn concentrations among the twelve provenances (p<0.05), while there is no significant difference between Cu and Se concentrations. A significant difference was also observed in the concentrations of five microelements at the different sampling times (p<0.001), but the mean concentrations for each microelement showed different temporal dynamic patterns. Meanwhile, a significant correlation between concentrations of Se and other measured microelements was detected in the leaves of C. paliurus, except for Mn. Obtained results not only demonstrated that leaves of C. paliurus exhibited higher levels of microelements (Fe, Mn, Cu, Zn and Se), but also provided a basis for breeding strategies of superior provenances with rich content of microelements, and choosing optimum harvesting time for food industry in future.