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植物研究 ›› 2021, Vol. 41 ›› Issue (3): 329-335.doi: 10.7525/j.issn.1673-5102.2021.03.002

• 研究报告 • 上一篇    下一篇

濒危植物瑶山苣苔的大小孢子发生和雌雄配子体发育研究

施慧嫒, 陈发菊, 梁宏伟, 王玉兵()   

  1. 三峡区域植物遗传与种质创新重点实验室/三峡大学生物技术研究中心,宜昌 443002
  • 收稿日期:2020-10-08 出版日期:2021-05-20 发布日期:2021-03-24
  • 通讯作者: 王玉兵 E-mail:tomswfc1977@163.com
  • 作者简介:施慧嫒(1995—),女,硕士,主要从事植物多样性保护研究。
  • 基金资助:
    国家自然基金(31000146)

Sporogenesis and Gametogenesis on Endangered Dayaoshania cotinifolia

Hui-Ai SHI, Fa-Ju CHEN, Hong-Wei LIANG, Yu-Bing WANG()   

  1. Key Laboratory of Three Gorges Regional Plant Genetics&Germplasm Enhancement(CTGU)/Biotechnology Research Center,China Three Gorges University,Yichang 443002
  • Received:2020-10-08 Online:2021-05-20 Published:2021-03-24
  • Contact: Yu-Bing WANG E-mail:tomswfc1977@163.com
  • About author:SHI Hui-Ai(1995—),female,master,mainly engaged in plant diversity conservation research.
  • Supported by:
    National Natural Science Foundation of China(31000146)

摘要:

利用石蜡切片技术对瑶山苣苔大小孢子发生、雌雄配子体发育及胚胎发育进行了细胞学观察,结果表明:瑶山苣苔胚珠倒生,单珠被,薄珠心,具珠被绒毡层。大孢子母细胞减数分裂形成的四分体呈直线排列,合点端的大孢子发育为功能大孢子,其余3个大孢子退化,胚囊为单孢子发生的蓼型胚囊发育方式。花药为四囊形,花药壁由外到内依次为表皮、药室内壁、中层和腺质绒毡层,小孢子形成时胞质分裂为修饰性同时型,小孢子四分体排列方式为四面体形,成熟花粉为2核细胞。胚乳发育为细胞型,在胚的发育过程中被吸收耗尽。瑶山苣苔大小孢子发生和雌雄配子体发育基本正常,不是导致其濒危的原因。但瑶山苣苔果实成熟时,胚仅发育至球形胚时期,需要经过一定时间休眠才能完成形态后熟,表明胚未发育完全可能是该物种天然更新困难的原因之一。

关键词: 瑶山苣苔, 大孢子发生, 小孢子发生, 雌配子体, 雄配子体

Abstract:

To explore the possible endangered embryology causes of Dayaoshania cotinifolia , the paraffin section method to observe mega-microsporogenesis, development of female and male gametophyte, and embryogenesis was employed. The main results as follows: The ovules were anatropous, single integument, thin nucellus, and with an integument tapetum. The megaspore mother cell had undergone meiotic divisions and developed into a linear tetrad. The chalazal megaspore of the tetrad was functional one and developed into a Polygonum type embryo-sac, another 3 megaspores degenerated. The anther was tetraposiform, the anther wall was composed with an epidermis, endothecium, two-layered middle layer, and a glandular tapetum. In the meiosis of microsporocyte, cytokinesis was a modified simultaneous type. The tetrads were tetrahedral and mature pollen grain was two-celled. The development of endosperm was cellular type and exhausted during embryo development. The process of the mega-microsporogenesis and development of female and male gametophyte of D.cotinifolia were normal, which was not the cause of its endangerment. The embryo developed to the globular embryonic stage at ripe fruit, the morphological after-ripening process of the embryo could be completed after dormancy. The undeveloped embryo might be one of the reasons for the difficulty of natural regenerates naturally.

Key words: Dayaoshania cotinifolia, megasporogenesis, microsporogenesis, female gametophyte, male game-tophyte

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