2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae).
Autor(a) principal: | |
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Data de Publicação: | 2007 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
Texto Completo: | http://www.alice.cnptia.embrapa.br/alice/handle/doc/326409 |
Resumo: | Microsporogenesis of several Brachiaria species of the Brazilian collection at Embrapa Beef Cattle has been analyzed in detail. This paper reports abnormal cytokinesis in three accessions of three different species (Brachiaria humidicola, 2n = 4x = 36, Brachiaria decumbens, 2n = 4x = 36, and Brachiaria dura, 2n = 6x = 54). Chromosomes paired in bi-, tri-, and quadrivalents in these accessions, whereas chromosome segregation at meiosis I was characterized by exclusion of laggards as micronuclei. In a high number of meiocytes, the first sign of cytokinesis appeared only in metaphase II and did not divide the meiocyte into a dyad. Total absence of cytokinesis was also detected among meiocytes in the second division. Since in both cases the two metaphase plates were very close, they favored the rejoining of chromosome sets after anaphase II and formed a restitutional nucleus in telophase II. Second cytokinesis occurred after telophase II in most meiocytes. Monads, dyads, and triads with n or 2n nuclei were observed among meiotic products. The 2n gametes observed correspond to the first division restitution (FDR). The number of affected cells in each accession was variable, but the number of microspores with restitutional nucleus, including those scored in tetrads and the released ones, did not exceed 9%. Although polyploidy is common in the genus Brachiaria, its origin is still unclear. Current results suggest that 2n gametes may have contributed to the evolutionary history of the genus. |
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2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae).BraquiáriaBrachiaria duraCampo GrandeMato Grosso do SulBrasilFeed cropsFeed grassesBrachiaria HumidicolaBrachiaria DecumbensCitogenética VegetalGramínea ForrageiraMelhoramento Genético VegetalPoliploidiaPlanta ForrageiracytogeneticsBrazilplant breedingpolyploidyMicrosporogenesis of several Brachiaria species of the Brazilian collection at Embrapa Beef Cattle has been analyzed in detail. This paper reports abnormal cytokinesis in three accessions of three different species (Brachiaria humidicola, 2n = 4x = 36, Brachiaria decumbens, 2n = 4x = 36, and Brachiaria dura, 2n = 6x = 54). Chromosomes paired in bi-, tri-, and quadrivalents in these accessions, whereas chromosome segregation at meiosis I was characterized by exclusion of laggards as micronuclei. In a high number of meiocytes, the first sign of cytokinesis appeared only in metaphase II and did not divide the meiocyte into a dyad. Total absence of cytokinesis was also detected among meiocytes in the second division. Since in both cases the two metaphase plates were very close, they favored the rejoining of chromosome sets after anaphase II and formed a restitutional nucleus in telophase II. Second cytokinesis occurred after telophase II in most meiocytes. Monads, dyads, and triads with n or 2n nuclei were observed among meiotic products. The 2n gametes observed correspond to the first division restitution (FDR). The number of affected cells in each accession was variable, but the number of microspores with restitutional nucleus, including those scored in tetrads and the released ones, did not exceed 9%. Although polyploidy is common in the genus Brachiaria, its origin is still unclear. Current results suggest that 2n gametes may have contributed to the evolutionary history of the genus.CNPGC.Patrícia Helena Gallo, UEM; Pamela Lonardoni Micheletti, UEM; Kellen Regina Boldrini, UEM; Claudicéia Risso-Pascotto, UEM; Maria Suely Pagliarini, UEM; Cacilda Borges do Valle, CNPGC.GALLO, P. HMICHELETTI, P. L.BOLDRINI, K. R.RISSO-PASCOLOTTO, C.PAGLIARINI, M. S.VALLE, C. B. do2011-07-22T01:04:31Z2011-07-22T01:04:31Z2008-02-0120072011-07-22T01:04:31Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleEuphytica, Wageningen, Holanda, v. 154, n. 2, p. 255-260, 2007.http://www.alice.cnptia.embrapa.br/alice/handle/doc/326409enginfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa)instacron:EMBRAPA2017-08-15T22:19:45Zoai:www.alice.cnptia.embrapa.br:doc/326409Repositório InstitucionalPUBhttps://www.alice.cnptia.embrapa.br/oai/requestopendoar:21542017-08-15T22:19:45falseRepositório InstitucionalPUBhttps://www.alice.cnptia.embrapa.br/oai/requestcg-riaa@embrapa.bropendoar:21542017-08-15T22:19:45Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa)false |
dc.title.none.fl_str_mv |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
title |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
spellingShingle |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). GALLO, P. H Braquiária Brachiaria dura Campo Grande Mato Grosso do Sul Brasil Feed crops Feed grasses Brachiaria Humidicola Brachiaria Decumbens Citogenética Vegetal Gramínea Forrageira Melhoramento Genético Vegetal Poliploidia Planta Forrageira cytogenetics Brazil plant breeding polyploidy |
title_short |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
title_full |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
title_fullStr |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
title_full_unstemmed |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
title_sort |
2n Gamete formation in the genus Brachiaria (Poaceae: Paniceae). |
author |
GALLO, P. H |
author_facet |
GALLO, P. H MICHELETTI, P. L. BOLDRINI, K. R. RISSO-PASCOLOTTO, C. PAGLIARINI, M. S. VALLE, C. B. do |
author_role |
author |
author2 |
MICHELETTI, P. L. BOLDRINI, K. R. RISSO-PASCOLOTTO, C. PAGLIARINI, M. S. VALLE, C. B. do |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Patrícia Helena Gallo, UEM; Pamela Lonardoni Micheletti, UEM; Kellen Regina Boldrini, UEM; Claudicéia Risso-Pascotto, UEM; Maria Suely Pagliarini, UEM; Cacilda Borges do Valle, CNPGC. |
dc.contributor.author.fl_str_mv |
GALLO, P. H MICHELETTI, P. L. BOLDRINI, K. R. RISSO-PASCOLOTTO, C. PAGLIARINI, M. S. VALLE, C. B. do |
dc.subject.por.fl_str_mv |
Braquiária Brachiaria dura Campo Grande Mato Grosso do Sul Brasil Feed crops Feed grasses Brachiaria Humidicola Brachiaria Decumbens Citogenética Vegetal Gramínea Forrageira Melhoramento Genético Vegetal Poliploidia Planta Forrageira cytogenetics Brazil plant breeding polyploidy |
topic |
Braquiária Brachiaria dura Campo Grande Mato Grosso do Sul Brasil Feed crops Feed grasses Brachiaria Humidicola Brachiaria Decumbens Citogenética Vegetal Gramínea Forrageira Melhoramento Genético Vegetal Poliploidia Planta Forrageira cytogenetics Brazil plant breeding polyploidy |
description |
Microsporogenesis of several Brachiaria species of the Brazilian collection at Embrapa Beef Cattle has been analyzed in detail. This paper reports abnormal cytokinesis in three accessions of three different species (Brachiaria humidicola, 2n = 4x = 36, Brachiaria decumbens, 2n = 4x = 36, and Brachiaria dura, 2n = 6x = 54). Chromosomes paired in bi-, tri-, and quadrivalents in these accessions, whereas chromosome segregation at meiosis I was characterized by exclusion of laggards as micronuclei. In a high number of meiocytes, the first sign of cytokinesis appeared only in metaphase II and did not divide the meiocyte into a dyad. Total absence of cytokinesis was also detected among meiocytes in the second division. Since in both cases the two metaphase plates were very close, they favored the rejoining of chromosome sets after anaphase II and formed a restitutional nucleus in telophase II. Second cytokinesis occurred after telophase II in most meiocytes. Monads, dyads, and triads with n or 2n nuclei were observed among meiotic products. The 2n gametes observed correspond to the first division restitution (FDR). The number of affected cells in each accession was variable, but the number of microspores with restitutional nucleus, including those scored in tetrads and the released ones, did not exceed 9%. Although polyploidy is common in the genus Brachiaria, its origin is still unclear. Current results suggest that 2n gametes may have contributed to the evolutionary history of the genus. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007 2008-02-01 2011-07-22T01:04:31Z 2011-07-22T01:04:31Z 2011-07-22T01:04:31Z |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
Euphytica, Wageningen, Holanda, v. 154, n. 2, p. 255-260, 2007. http://www.alice.cnptia.embrapa.br/alice/handle/doc/326409 |
identifier_str_mv |
Euphytica, Wageningen, Holanda, v. 154, n. 2, p. 255-260, 2007. |
url |
http://www.alice.cnptia.embrapa.br/alice/handle/doc/326409 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa) instacron:EMBRAPA |
instname_str |
Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
instacron_str |
EMBRAPA |
institution |
EMBRAPA |
reponame_str |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
collection |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
repository.name.fl_str_mv |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
repository.mail.fl_str_mv |
cg-riaa@embrapa.br |
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1794503346131828736 |