Acta Scientiarum Naturalium Universitatis Pekinensis

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Cytological Studies on the Formation of Female Gametophyte and Development of Archegonia in Ginkgo Biloba

JI Chengjun, YANG Xiong, LI ZhengliLee CL   

  1. College of Life Sciences Peking University, Beijing, 100871
  • Received:1998-05-28 Online:1999-07-20 Published:1999-07-20



  1. 北京大学生命科学学院,北京,100871

Abstract: Following approximately a dozen of multiple divisions of producing about 2000 nuclei, the cell wall of the female gametophyte of Ginkgo biloba began to form centripedally. The archegonial initials could be distinguished from the peripheral cells at the micropyle end of the female gametophyte before the completion of the wall formation where the cell wall had reached the center of the gametophyte. Usually there were two archegonia in a female gametophyte which developed asynchronously at first, and gradually developed in concert. Great structural and morphological changes in the neck cell and the central cell took place during the archegonial development. The two neck cells of the archegonium divided to form four neck cells before fertilization, this division happened prior to the division of the central cell, but at times they divided synchronously. The initiation and development of archegonia in Gingko, compared with those of cycads, were liked to be more primitive at the evolutional level.

Key words: Ginkgo biloba, archegonia, female gametopyhte, structure development

摘要: 银杏(Ginkg biloba L.)的功能大孢子经10多次游离核分裂,形成约2000个核后,向心地形成细胞壁。雌配子体中游离核之间细胞壁还未完全形成时,在其近珠孔端表面可看到颈卵器母细胞发生。一个雌配子体中的颈卵器数目通常为2个,它们的发育最初不同步,以后逐渐趋向一致。在颈卵器的发育过程中,颈细胞和中央细胞的形态及结构都发生了较大的变化。颈卵器的2个颈细胞在受精前进行一次斜向分裂形成4个颈细胞,此分裂一般早于中央细胞的分裂,偶尔也可见颈细胞和中央细胞同时分裂。银杏雌配子体及颈卵器的发生与发育,和苏铁类植物比较,在演化程度上可能更为原始。

关键词: 银杏, 雌配子体, 颈卵器, 结构发育

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