.
| Autor(a) principal: | |
|---|---|
| Data de Publicação: | 1996 |
| Outros Autores: | |
| Tipo de documento: | Artigo |
| Idioma: | por |
| Título da fonte: | Biotemas (Online) |
| Texto Completo: | https://periodicos.ufsc.br/index.php/biotemas/article/view/22030 |
Resumo: | The anthers are tetrasporangiate and the anther wall comprises five layers - epidermis, enfothecium, two middle layers and tapetum. Anther wall formation is of the basic type. At late stage the glandular (secretory) tapetum cells become binucleate and ultimately degenerated. As microsporogenesis progresses, middle layers become crushed and absorbed so that in the mature anther only the epidermis and endothecium remain intact. Tetrahedral tetrads are formed by simultaneous cytokinesis, followed by dissolution of callose and release of microspores. After microspore mitosis, pollen is shed at the two-celled stage. Mature endothecial cells are periclinally elongate, and moderate wall thickenings are present. C. brasiliense show two of the three evolutionary trends of the tapetum in Spermatophyta: 1) An intrusion of tapetum cells into the loculus, and 2) A better nutrition through direct contact with the spores in narrow anthers. |
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.O desenvolvimento das anteras e do gametofito masculino em Calophyllum brasiliense (Clusiaceae)The anthers are tetrasporangiate and the anther wall comprises five layers - epidermis, enfothecium, two middle layers and tapetum. Anther wall formation is of the basic type. At late stage the glandular (secretory) tapetum cells become binucleate and ultimately degenerated. As microsporogenesis progresses, middle layers become crushed and absorbed so that in the mature anther only the epidermis and endothecium remain intact. Tetrahedral tetrads are formed by simultaneous cytokinesis, followed by dissolution of callose and release of microspores. After microspore mitosis, pollen is shed at the two-celled stage. Mature endothecial cells are periclinally elongate, and moderate wall thickenings are present. C. brasiliense show two of the three evolutionary trends of the tapetum in Spermatophyta: 1) An intrusion of tapetum cells into the loculus, and 2) A better nutrition through direct contact with the spores in narrow anthers.As antenas são tetrasporangiadas e providas de uma parede constituida por cinco camadas - epiderme, endotécio, dois estratos de camada média e o tapete. O padrão de formação da parede da antera é do tipo básico. Nos estágios finais de seu desenvolvimento as células do tapete glandular (secretor) tornam-se binucleadas, e por fim degeneram. Na progressão da microsporogênese a camada média é comprimida e absorvida, sendo que na antera madura persistem apenas a epiderme e o endotécio. Tétrades tetraédricas são formadas através de citocinese simultânea, seguindo-se a dissolução da parede de calose e a liberação dos micrósporos. Após a divisão mitótica nos micrósporos o grão de pólen, no seu estágio bicelular, é liberado. As células do endotécio, quando maduras, são alongadas perielinalmente, e apresentam moderado espessamento fibroso. C. brasiliense mostra duas das três tendências evolutivas do tapete em espermatófita: 1) A intrusão das células do tapete no lóculo; 2) O contato direto com os esporos em virtude do aspecto estreito da antera, o que melhora as condições de nutrição dos micrósporos.Universidade Federal de Santa Catarina1996-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://periodicos.ufsc.br/index.php/biotemas/article/view/22030Biotemas; v. 9 n. 1 (1996); 81-892175-79250103-1643reponame:Biotemas (Online)instname:Universidade Federal de Santa Catarina (UFSC)instacron:UFSCporhttps://periodicos.ufsc.br/index.php/biotemas/article/view/22030/19971Copyright (c) 1996 João de Deus Medeiros, Sandra Cristina Müllerhttp://creativecommons.org/licenses/by/4.0info:eu-repo/semantics/openAccessMedeiros, João de DeusMüller, Sandra Cristina2022-11-18T13:01:08Zoai:periodicos.ufsc.br:article/22030Revistahttp://www.biotemas.ufsc.br/index.htmPUBhttps://periodicos.ufsc.br/index.php/biotemas/oai||carlospinto@ccb.ufsc.br2175-79250103-1643opendoar:2022-11-18T13:01:08Biotemas (Online) - Universidade Federal de Santa Catarina (UFSC)false |
| dc.title.none.fl_str_mv |
. O desenvolvimento das anteras e do gametofito masculino em Calophyllum brasiliense (Clusiaceae) |
| title |
. |
| spellingShingle |
. Medeiros, João de Deus |
| title_short |
. |
| title_full |
. |
| title_fullStr |
. |
| title_full_unstemmed |
. |
| title_sort |
. |
| author |
Medeiros, João de Deus |
| author_facet |
Medeiros, João de Deus Müller, Sandra Cristina |
| author_role |
author |
| author2 |
Müller, Sandra Cristina |
| author2_role |
author |
| dc.contributor.author.fl_str_mv |
Medeiros, João de Deus Müller, Sandra Cristina |
| description |
The anthers are tetrasporangiate and the anther wall comprises five layers - epidermis, enfothecium, two middle layers and tapetum. Anther wall formation is of the basic type. At late stage the glandular (secretory) tapetum cells become binucleate and ultimately degenerated. As microsporogenesis progresses, middle layers become crushed and absorbed so that in the mature anther only the epidermis and endothecium remain intact. Tetrahedral tetrads are formed by simultaneous cytokinesis, followed by dissolution of callose and release of microspores. After microspore mitosis, pollen is shed at the two-celled stage. Mature endothecial cells are periclinally elongate, and moderate wall thickenings are present. C. brasiliense show two of the three evolutionary trends of the tapetum in Spermatophyta: 1) An intrusion of tapetum cells into the loculus, and 2) A better nutrition through direct contact with the spores in narrow anthers. |
| publishDate |
1996 |
| dc.date.none.fl_str_mv |
1996-01-01 |
| dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
| format |
article |
| status_str |
publishedVersion |
| dc.identifier.uri.fl_str_mv |
https://periodicos.ufsc.br/index.php/biotemas/article/view/22030 |
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https://periodicos.ufsc.br/index.php/biotemas/article/view/22030 |
| dc.language.iso.fl_str_mv |
por |
| language |
por |
| dc.relation.none.fl_str_mv |
https://periodicos.ufsc.br/index.php/biotemas/article/view/22030/19971 |
| dc.rights.driver.fl_str_mv |
Copyright (c) 1996 João de Deus Medeiros, Sandra Cristina Müller http://creativecommons.org/licenses/by/4.0 info:eu-repo/semantics/openAccess |
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Copyright (c) 1996 João de Deus Medeiros, Sandra Cristina Müller http://creativecommons.org/licenses/by/4.0 |
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openAccess |
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application/pdf |
| dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Catarina |
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Universidade Federal de Santa Catarina |
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Biotemas; v. 9 n. 1 (1996); 81-89 2175-7925 0103-1643 reponame:Biotemas (Online) instname:Universidade Federal de Santa Catarina (UFSC) instacron:UFSC |
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Biotemas (Online) |
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Biotemas (Online) - Universidade Federal de Santa Catarina (UFSC) |
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