穗花牡荆花芽分化过程中形态和生理指标变化

以穗花牡荆为研究材料,通过探究其花芽分化进程和生理特性,为花期调控技术提供成花机理。采用物候期观察和石蜡切片相结合的方法并测定花芽分化过程中相关生理指标,研究花发育过程中的形态和生理变化。结果表明,穗花牡荆花芽分化为一年多次分化型,其进程可划分为七个时期：未分化期、总轴花序原基分化期、初级分轴花序原基分化期、次级分轴花序原基分化期、小花原基分化期、花器官分化前期和花器官分化后期。同一植株不同位置花芽及同一花序中不同单花分化的进程不同,第一季花期后各阶段的花芽分化形态常存在重叠。花芽分化过程中不同时期叶片和花芽的可溶性糖和可溶性蛋白质含量均有上升下降的变化,总体上叶片中营养物质含量高于花芽保证营养供应。花芽分化过程中,IAA、ABA、CTK和GA3整体水平上先升后降有利于花芽分化进行。研究认为,花芽中大量的可溶性糖和蛋白质积累及较高的碳氮比,有利于穗花牡荆花芽形态分化顺利完成。低水平的GA3/ABA和IAA/CTK有利于花序的形成,ABA/CTK和ABA/IAA比值升高促进小花原基和小花萼片原基的分化, GA3/CTK、GA3/ABA和GA3/IAA比值升高促进花瓣原基、雄雌蕊原基发育。

Study on the Changes of Morphological and Physiological Indexes during Flower Bud Differentiation of Vitex agnus-castus

Using Vitex agnus-castus as the research material, we explored the flower bud differentiation process and its physiological characteristics to provide the basis for flowering regulation technology. The morphological and physiological changes during flower development were studied by combining phenophase observation with the paraffin section and measuring the relevant physiological indexes during flower bud differentiation. The results showed that the flower bud differentiation process can be divided into seven stages: undifferentiated stage, total axis inflorescence primordium differentiation stage, primary axis inflorescence primordium differentiation stage, secondary axis inflorescence primordium differentiation stage, microfloral primordial differentiation stage, early and later floral organ differentiation stage, which are multiple differentiation types in one year. The process of flower bud differentiation in different positions of the same plant and single flowers in the same inflorescence is different. The flower bud differentiation forms at different stages after the first season of flowering and often overlaps. The contents of soluble sugar and soluble protein in leaves and flower buds increased and decreased at different stages of flower bud differentiation. In general, the nutrient content in leaves was higher than that in flower buds to ensure nutrient supply. During flower bud differentiation, the overall levels of IAA, ABA, CTK, and GA3 first increased and then decreased, beneficial to flower bud differentiation. It is believed that the accumulation of a large amount of soluble sugar and protein in flower buds and the high carbon-nitrogen ratio is conducive to the smooth completion of flower bud differentiation of Vitex agnus-castus. Low levels of GA3/ ABA and IAA / CTK were advantageous to inflorescence formation. The ratio of ABA / CTK and ABA / IAA increased during the floral primordium differentiation stage and sepal primordium stage. Petal primordium and stamen primordium differentiation needed higher GA3/ CTK, GA3 / ABA, and GA3 / IAA ratios.