Abstract:

Objective: In this study, we investigated the distribution regularity of mineral elements in different plant organs and gender differences between male and female plants of Fraxinus velutina, in order to provide a theoretical basis for further elucidating the physiological mechanism of the difference in growth of female and male plants of Fraxinus velutina. Method: The dynamics of mineral element (K, Ca, Na, Mg) contents in different organs of male and female plants of Fraxinus velutina were compared.Result: The result presented in the following four aspects:1) The K content in different organs of Fraxinus velutina was in order of fruit > leaf > branch during the growing season from May to November. However, the order of Ca and Mg in different organs of Fraxinus velutina in each months during the growing season was leaf > branch > fruit. From May to June, the order of Na content in different organs was leaf > fruit > branch, while in the middle and late growing season the order of Na content in different organs was leaf > branch > fruit. During the growing season, the K content in the leaves of Fraxinus velutina decreased with time, the contents of Ca and Na in leaves increased with time, and the Mg content of leaves remained stable. 2) Comparison of mineral elements contents in leaves of male and female plants of Fraxinus velutina showed that, the K, Ca, Na and Mg contents of male plants were higher than those of female plants in each month during the growing season, but this difference was significant only in some months of the growing season. 3) Correlation analysis of mineral elements contents in the same organ of Fraxinus velutina showed that, the leaf K content was significantly negatively correlated with leaf Ca and Mg content respectively, while leaf Ca and leaf Mg contents showed a significantly positive correlation. There was no significant correlation between Na content and other elements contents in leaves. Similar to leaves, there was a significantly negative correlation between fruit K and fruit Ca content, while the fruit Ca and fruit Mg content showed a significantly positive correlation. 4) Correlation analysis of mineral elements in different organs of Fraxinus velutina showed that, there were significant positive correlations between leaf K content and branch K content, leaf Na content and branch Na content of both male and female plants. There were significantly and extremely significant positive correlations between leaf Ca content and fruit Ca content, leaf Mg content and fruit Mg content of female plants respectively. There was a significant positive correlation between Na content in leaves and Na content in branches of both male and female plants. Objective: The result showed that there were differences in the distribution of mineral elements between male and female organs of Fraxinus velutina. In the growing season, the mineral element content in leaves of male plants was mostly higher than that of female plants.The female plants bore a large number of fruits and participated in a large proportion of mineral nutrition distribution, which might be the important factor affecting the mineral element content in leaves. The correlation analysis of different element contents in the same organ showed that there was a significant correlation between K, Ca and Mg contents in either leaves or fruits. The knowledge of the proportion distribution of mineral elements among different organs and the relationship is the premise to clarify the physiological mechanism of gender growth difference, and is also the focus of future research.

Key words: Fraxinus velutina, male and female plants, mineral elements, dynamic changes, plant organs