毛棉杜鹃芽形态分化期间封顶叶内源激素含量变化的研究

Quantitative variation of endogenous hormones in Rhododendron moulmainense Hook.f.leaf under buds during buds morphological differentiation

本研究观察了毛棉杜鹃（Rhododendron moulmainense Hook.f.）花芽与叶芽的分化进程,测定了花芽和叶芽形态分化过程中封顶叶内源赤霉素（GA3）、生长素（IAA）、脱落酸（ABA）和玉米素核苷（ZR）的含量变化,探讨了毛棉杜鹃花芽分化与内源植物激素的关系。结果表明：毛棉杜鹃花芽分化与叶芽分化形态特征与所持续的时间明显不同,花芽分化时期从7月中下旬至9月中旬,历时约40～45 d,而叶芽分化持续35～40 d;在花芽和叶芽形态分化期,花芽封顶叶的ABA和ZR含量明显比叶芽封顶叶的高,而且其含量呈显著上升趋势,而GA3和IAA则相反,花芽封顶叶中ABA/GA3、ABA/IAA、ZR/GA3和ZR/IAA的比值都明显高于叶芽,并呈显著上升趋势,表明封顶叶内源激素及其各自之间的平衡关系对毛棉杜鹃的花芽形态分化起着重要的调控作用。

Based on the observation of the morphological differentiation process of flower buds and leaf buds of Rhododendron moulmainense Hook.f.,the content of endogenous hormones like gibberellin（GA3）,indolylacetic acid（IAA）,abscisic acid（ABA） and zeatin（ZR） within the leaves respectively under flower buds and leaf buds at the different stages of flower buds and leaf buds morphological differentiation process was determined;The relationship between these endogenous hormones and flower buds morphological diferentiation was discussed.The results showed that the morphological characteristics and duration of flower buds and leaf buds were different.The differentiation process of flower buds lasted for about 40-45 days from the end of July to the mid-September,while the differentiation process of leaf buds lasted for about 35-40 days.The content of ABA and ZR in leaves under flower buds was higher than the content in leaves under leaf buds,and showed a rising tendency during the flower buds and leaf buds morphological differentiation process,While the contents of GA3 and IAA showed an opposite result and tendency.The ratios of ABA/GA3,ABA/IAA,ZR/GA3,ZR/IAA in the leaves under flower buds was obviously higher than those in the leaves under leaf buds and showing a rising tendency.This illustrated the balance between diferent endogenous hormones also played an important role in regulating and controlling flower buds diferentiation of Rhododendron moulmainense Hook.f..