生物多样性 ›› 2011, Vol. 19 ›› Issue (5): 551-557.DOI: 10.3724/SP.J.1003.2011.07035

• 研究报告 • 上一篇    下一篇

二重雌雄异型异熟物种色木槭3种表型花的细胞形态学研究

张灵芝1,2, 商辉1,2, 罗毅波1, 程鑫3, 白伟宁1,*()   

  1. 1中国科学院植物研究所系统与进化植物学国家重点实验室, 北京 100093
    2中国科学院研究生院, 北京 100049
    3辽宁省抚顺市林业局, 辽宁抚顺 113000
  • 收稿日期:2011-03-02 接受日期:2011-06-14 出版日期:2011-09-20 发布日期:2011-10-08
  • 通讯作者: 白伟宁
  • 作者简介:*E-mail: baiwn@ibcas.ac.cn
  • 基金资助:
    国家自然科学基金(30970436)

Morphology and cytology of three flower phenotypes in a duodichogamous tree species, Acer mono

Zhang Lingzhi1,2, Shang Hui1,2, Luo Yibo1, Cheng Xin3, Bai Weining1,*()   

  1. 1State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
    2Graduate University of the Chinese Academy of Sciences, Beijing 100049
    3Forestry Department of Fushun Municipality in Liaoning Province, Fushun, Liaoning 113000
  • Received:2011-03-02 Accepted:2011-06-14 Online:2011-09-20 Published:2011-10-08
  • Contact: Bai Weining

摘要:

二重雌雄异型异熟, 即雌雄功能按雄-雌-雄顺序分别表达, 是有花植物中较为少见的异熟机制。槭属(Acer)大部分物种具有二重雌雄异型异熟的开花物候, 且第一期雄花与第二期在形态上差别较大。为深入探讨花发育模式对花形态和开花物候的影响, 本文应用石蜡切片技术和光镜技术, 对色木槭(Acer mono)各个发育时期的3种类型花(雄花I, II和雌花)的形态学和细胞学进行观察比较。结果发现: 色木槭一期雄花(雄I)在大孢子四分体退化形成功能性大孢子时期, 子房萎缩并迅速退化消失; 而二期雄花(雄II)在此时期胚珠和子房表现为逐渐退化败育, 但成熟子房内仅剩蘑菇云状的败育胚珠, 形态上可见子房和二分裂柱头; 雌花由于绒毡层延缓解体, 并缺少与花药开裂有关的唇细胞, 导致成熟花药无法开裂散粉, 发生了结构性的雄性不育。结果表明, 色木槭的3种类型的花均起源于两性花, 在花发育过程中通过成熟花药的不开裂和子房胚珠的败育分别产生功能性雌花或雄花, 而雄I和雄II在形态上的差异, 是由子房是否迅速退化造成的。

关键词: Acer mono, 二重雌雄异型异熟, 功能性雌花或雄花, 细胞形态学

Abstract

Duodichogamy, where individual plants produce two batches of male flowers that are temporally separated by a batch of female flowers, is the rarest temporal sexual system in flowering plants. Duodichogamy is present in some species of Acer, whose flowers of the first (male I) and second male phases (male II) differ morphologically. To explore the influence of floral development on flower morphology and phenology, we used paraffin methods and light microscopy to compare morphological and cytological differences among male (I and II) and female flowers at different developmental stages. Our main results were as follows: the ovary of male I degenerated and disappeared quickly upon megaspore tetrad degeneration, and developed into macrosporocytes; while the ovary of male II degenerated gradually during this period and only traces of residual ovule remained in the fully-developed ovary; the failure of anthers of female flowers to dehisce might be caused by retardant degeneration of tapetum tissue and loss of lip cells, i.e. formation sterility. In conclusion, both pistil and stamen primordial could be found in male (I and II) and female flower buds at early phases of sex differentiation, but selective abortion occurred in later developmental phases.

Key words: Acer mono, duodichogamy, functional male and female flowers, morphology, cytology