An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla
The development of megasporocarps of Azolla microphylla, after the retention of a single functional megaspore within the megasporangium, was studied by light and transmission electron microscopy, using material grown under controlled conditions. The young megaspore contained a thin layer of cytoplas...
| Autores principales: | , , |
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| Formato: | Journal Article |
| Lenguaje: | Francés |
| Publicado: |
Canadian Science Publishing
1986
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| Acceso en línea: | https://hdl.handle.net/10568/167749 |
| _version_ | 1855523498739367936 |
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| author | Herd, Y.R. Cutter, E.G. Watanabe, I. |
| author_browse | Cutter, E.G. Herd, Y.R. Watanabe, I. |
| author_facet | Herd, Y.R. Cutter, E.G. Watanabe, I. |
| author_sort | Herd, Y.R. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | The development of megasporocarps of Azolla microphylla, after the retention of a single functional megaspore within the megasporangium, was studied by light and transmission electron microscopy, using material grown under controlled conditions. The young megaspore contained a thin layer of cytoplasm with various organelles and was bounded by a thin exine. It was surrounded by a dense periplasmodial tapetum, which consisted of a peripheral vacuolate region, containing degenerated megaspores, a middle region containing nuclei and large organelles such as amyloplasts and mitochondria, and an inner zone, invaginated round the spore, comprising microtubules, ribosomes, and coated vesicles. At a later stage the exine increased in thickness, and greater vacuolation occurred at the periphery of the periplasmodium. The endoperine was formed by deposition of granular material between the exine and the periplasmodium, and further granular material deposited in small vacuoles gave rise to the exoperine. The floats were formed from three (tapetal) membrane-bounded chambers, in which granular material gradually became organised to form the pseudocells. Characteristic exoperinal filaments were formed in channels in the periplasmodium, which was eventually completely used up in the formation of floats, collar, and megaspore wall, in which sporopollenin was probably present. The megaspore itself became engorged with cytoplasm and storage products such as lipid and starch. Cells of Anabaena with relatively thick walls were present between the megasporangial wall and the indusium. |
| format | Journal Article |
| id | CGSpace167749 |
| institution | CGIAR Consortium |
| language | Francés |
| publishDate | 1986 |
| publishDateRange | 1986 |
| publishDateSort | 1986 |
| publisher | Canadian Science Publishing |
| publisherStr | Canadian Science Publishing |
| record_format | dspace |
| spelling | CGSpace1677492025-05-14T10:39:39Z An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla Herd, Y.R. Cutter, E.G. Watanabe, I. The development of megasporocarps of Azolla microphylla, after the retention of a single functional megaspore within the megasporangium, was studied by light and transmission electron microscopy, using material grown under controlled conditions. The young megaspore contained a thin layer of cytoplasm with various organelles and was bounded by a thin exine. It was surrounded by a dense periplasmodial tapetum, which consisted of a peripheral vacuolate region, containing degenerated megaspores, a middle region containing nuclei and large organelles such as amyloplasts and mitochondria, and an inner zone, invaginated round the spore, comprising microtubules, ribosomes, and coated vesicles. At a later stage the exine increased in thickness, and greater vacuolation occurred at the periphery of the periplasmodium. The endoperine was formed by deposition of granular material between the exine and the periplasmodium, and further granular material deposited in small vacuoles gave rise to the exoperine. The floats were formed from three (tapetal) membrane-bounded chambers, in which granular material gradually became organised to form the pseudocells. Characteristic exoperinal filaments were formed in channels in the periplasmodium, which was eventually completely used up in the formation of floats, collar, and megaspore wall, in which sporopollenin was probably present. The megaspore itself became engorged with cytoplasm and storage products such as lipid and starch. Cells of Anabaena with relatively thick walls were present between the megasporangial wall and the indusium. 1986-04-01 2024-12-19T12:57:40Z 2024-12-19T12:57:40Z Journal Article https://hdl.handle.net/10568/167749 fr Canadian Science Publishing Herd, Y. R.; Cutter, E. G. and Watanabe, I. 1986. An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla. Can. J. Bot., Volume 64 no. 4 p. 822-833 |
| spellingShingle | Herd, Y.R. Cutter, E.G. Watanabe, I. An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title | An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title_full | An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title_fullStr | An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title_full_unstemmed | An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title_short | An ultrastructural-study of postmeiotic development in the megasporocarp of azolla-microphylla |
| title_sort | ultrastructural study of postmeiotic development in the megasporocarp of azolla microphylla |
| url | https://hdl.handle.net/10568/167749 |
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