毛棉杜鹃花芽分化期叶片C、N、P质量分数的变化

Changes in Carbon,Nitrogen and Phosphorus Contents in Rhododendron moulmainense Leaves during Flower Bud Differentiation

观察了毛棉杜鹃(Rhododendron moulmainense Hook.f.)花芽和叶芽分化过程,测定了花芽分化各时期花芽和叶芽封顶叶的总糖、总氮、可溶性蛋白和磷的质量分数,探讨了C、N、P等营养物质与毛棉杜鹃花芽分化的关系。结果表明,在整个花芽分化期,花芽封顶叶的总糖和磷质量分数明显高于叶芽封顶叶,而且其质量分数呈上升趋势;而总氮则相反;花芽和叶芽封顶叶的可溶性蛋白质量分数的变化趋势比较接近,但质量分数则是花芽封顶叶的高,并且在分化的关键时期都出现了明显的峰值和低谷值。在花芽进入分化期之后,花芽封顶叶的碳氮比和磷氮比都明显高于叶芽封顶叶,并呈上升趋势。说明这几种营养物质及其比例在毛棉杜鹃花芽分化过程中起着重要的基础作用。

A study was conducted to determine the contents of total sugar, total nitrogen, soluble protein, and phosphorus of the leaves under flower＇buds and leaf buds at different stages of flower bud differentiation based on the observation of differentiation process of flower buds and leaf buds of Rhododendron moulmainense Hook. f. The relationships between the nutrients （C, N, P） and flower bud differentiation were discussed. Results indicated that, during the process of flower bud differentiation, the contents of total sugar and phosphorus in the leaves under flower buds were obviously higher than those in the leaves under leaf buds, showing an increasing tendency. The contents of total nitrogen showed a decreasing tendency. The content of soluble protein in the leaves under flower buds was higher than that in the leaves under leaf buds, showing a similar changing tendency, and the maximum and minimum were observed at key differentiation stages. During the flower bud differentiation, the ratios of C/N and P/N in the leaves under flower buds were obviously higher than those in the leav- es under leaf buds, showing a rising tendency. It is indicated that the contents of these nutrients and their ratios play an important role in the flower bud differentiation of R. moulmainense.