Embryological studies in Anredera cordifolia (Ten.) Steenis (Basellaceae)
作者:
Raul Pozner,
Sara Maldonado,
期刊:
Giornale botanico italiano
(Taylor Available online 1989)
卷期:
Volume 123,
issue 1-2
页码: 39-48
ISSN:0017-0070
年代: 1989
DOI:10.1080/11263508909430245
出版商: Taylor & Francis Group
关键词: Anredera cordifolia;anther and ovule development;Basellaceae;embryology;embryo sac;megasporogenesis;microsporogenesis
数据来源: Taylor
摘要:
This paper deals with the ovule and anther structure, sporogenesis, and gametogenesis ofAnreda cordifolia(Ten.) Steenis. The conclusions are: the anther wall develops according to the Monocotyledonous type of Davis(1966). The tapetum is secretory and the endothecial cells develop U-form thickenings on radial and internal tangential walls. Microspore mother cells undergo simultaneous cytokinesis and the microspore tetrads are tetrahedral. Pollen grains are 3-celled when shed. At anthesis the ovule is orthoamphitropous crassinucellar and bitegmic with the micropyle formed by the inner integument. The archesporial cell cuts off a primary parietal cell which becomes the parietal tissue. A nucellar cap develops from the nucellar epidermis. The outer integument is dermal and subdermal in origin but the inner is only dermal. Only one archesporial cell differentiates from the nucellus, and the megaspores are arranged in T-tedrads. The chalazal megaspore produces an 8-nucleate embryo sac which develops according to thePolygonumtype. The mature synergids present a filiform apparatus that accords to the type. I following Cocucci(1981). The antipodal cells are ephemeral. Starch grains accumulate in the synergids, egg cell and central cell. Finally, the systematic value for Basellaceae of the embryological characters here considered, is discussed.
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