Sporogenesis and development of gametophytes in an endangered plant, Tetracentron sinense Oliv
Biol. Res
;
45(4): 393-398, 2012. ilus
Artigo
em Inglês
| LILACS
| ID: lil-668694
ABSTRACT
The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature pollen grains are two-celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinucellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Significantly, some striking features were first found in T. sinense (1) anther dehiscence occurs soon after the endothecium fibrously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-celled pollen grain; (3) a few cellular events such as the vacuolization and the contraction and deformation of the pollen mother cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Pólen
/
Magnoliopsida
/
Células Germinativas Vegetais
/
Gametogênese Vegetal
Idioma:
Inglês
Revista:
Biol. Res
Assunto da revista:
Biologia
Ano de publicação:
2012
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
China
Instituição/País de afiliação:
China West Normal University/CN
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