摘 要

为系统掌握常春二乔玉兰二次开花物候节律，探讨其与内含物的关系，本研究以6年生常春二乔玉兰为试验材料，观测其年生长发育节律、二次开花物候特性以及茎段内含物和内源激素含量的变化。研究表明：1)每年1月上旬至2月下旬为常春二乔玉兰休眠期，2月底为花芽初次萌动期。3月初次开花,4月初开始营养生长，5月初进行花芽分化，5月底部分花芽萌动并于6月再次开花，花后持续发育，并于9月进入落叶期;2)初次开花期间可溶性糖和可溶性蛋白呈下降趋势，淀粉含量于开花后期下降；二次开花期间可溶性糖和淀粉总体呈先降后升趋势，而可溶性蛋白总体呈下降趋势。3)初次开花期间IAA、ZR、IAA/ABA及(IAA GA)/ABA均呈下降趋势，GA和GA/ABA呈“升-降”趋势，而ABA呈“降-升”趋势；二次开花期间IAA、ZR和ABA均呈下降趋势，GA/ABA呈上升趋势，GA呈“升-降”趋势，而IAA/ABA和(IAA GA)/ABA呈“降-升”趋势。显而易见，常春二乔玉兰的两次开花模式具有较为显著地区别，而且和内含物、内源激素息息相关；受到内含物与内源激素的调控作用。首先低水平的可溶性糖及高水平的淀粉和可溶性蛋白有利于初次开花的启动，而低水平的可溶性蛋白及高水平的可溶性糖和淀粉含量则有利于再次开花的实现。其次内源激素的动态平衡与二次开花息息相关，GA和GA/ABA的升高有利于二次开花的启动；GA和ABA在二次开花期的含量差异是影响二次开花期花量与育性差异的可能因素。

关键词：常春二乔玉兰；二次开花；内含物；内源激素

Preliminary study on contributing factor of two times flowering in Magnolia ×soulangeana ‘Changchun’

ABSTRACT

In order to systematically mastered the phenological rhythm of two times flowering, and discussed its relationship with inclusions in Magnolia ×soulangeana ‘Changchun’, six years old Magnolia ×soulangeana ‘Changchun’ tree was taken as material. The annual growth and developmental rhythm, phenological character of two times flowering were observed, and also the changes of inclusions content in the stem were tested..The research were shown as follows：1）The dormant period of Magnolia ×soulangeana ‘Changchun’ was from early January to late February, then its flower buds began to burst in the end of February. The first flowering in March. Then the vegetation growth began in early April. The flower buds initiated differentiation in early May, and burst again at the end of May partly, followed by the secondary flowering in early June. After flowering, it continued to develop and entered the deciduous period in September.2)Soluble sugar and soluble protein was shown a trend of descending among first flowering, while starch content decreased at the late flowering stage. And the content of soluble sugar and starch was shown a trend of first descending then rising, while the soluble protein content continued to decline during the secondary flowering. 3)IAA, ZR, IAA/ABA and (IAA GA)/ABA was shown a trend of descending among first flowering. GA and GA/ABA were rising first and then decreasing. ABA was decreasing first and then rising. IAA, ZR and ABA were shown a trend of descending during the secondary flowering, while GA/ABA was on the rise. GA was rising first and then decreasing, however, IAA/ABA and (IAA GA)/ABA were decreasing first and then rising.

Obviously, the two flowering patterns of Magnolia ×soulangeana ‘Changchun’ have a more significant difference, and are closely related to the inclusions and endogenous hormones. in the same time，they are regulated by the inclusions and endogenous hormones.The frist,Low levels of soluble sugar and high levels of starch and soluble protein were beneficial to the initiation of first flowering; while low levels of soluble protein and high levels of soluble sugar and starch were contribute to the realization of secondary flowering.then, High level of GA and GA/ABA were beneficial to the initiation of two times flowering;Different content of GA and ABA at the two times flowering stages may be the factor that influence quantity and fertility of two times flowering.

Key words:Magnolia ×soulangeana‘Changchun’; two times flowering ; inclusions; endogenous hormone.

目 录

1 前言 1

2试验材料与方法 2

2.1 试验材料 2

2.2 试验方法 2

2.2.1基于形态监测的不同物候期划分 2

2.2.2生理指标测定 2

2.3数据分析 3

3结果与分析 4

3.1物候期动态 4

3.2二次开花模式差异 5

3.3 二次开花期内含物变化动态 6

3.3.1初次开花期内含物动态 6

3.3.2 再次开花期内含物动态 7

3.4 二次开花过程中内源激素含量变化 8

3.4.1 初次开花期内源激素动态 8

3.4.2 二次开花期内源激素动态 8

3.5二次开花期间内源激素比值的变化 9

4 讨论 11

4.1 常春二乔玉兰二次开花模式的特异性 11

4.2 二次开花模式与内含物的动态平衡 11

4.3 GA和ABA对二次开花及其模式差异的影响 12

4.4IAA和ZR对二次开花的影响 13

4.5 内源激素比值对二次开花的影响 13

结 论 15

致 谢 16

参考文献 17

1 前言

花期是指植物的花或花序绽放（开花）的一段时间，花和花序都是由花芽发育而来，其涉及植物营养生长向生殖生长不可逆的转变过程（成花），即茎尖在内部代谢途径和外在表型上发生一系列程序性转变，包括花器官各原基形成、分化、成熟，最终形成完整的花器官。成花与开花过程是在植物体内外因子的共同作用，相互协调下完成的^[1]。

目前的研究主要侧重于两个方面，一个是成花过程密切相关的内源激素和多胺的研究；二是成花过程中可溶性糖、淀粉、蛋白质等物质含量的变化^[2]。很多研究表明, 植物的开花过程是在内部遗传基因控制下营养与内源激素综合作用的结果。植物激素作为植物体内合成的微量有机物质，是植物自身合成的痕量生长调节分子的总称，它们的化学结构虽然比较简单，但却具有十分复杂的生理效应^[3]。它们通常在植物体内部分器官合成后运往作用部位，通过影响细胞的分裂、伸长、分化参与调控植物器官的形态建成。