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	Provedor de dados Ciência Rural (2) Genet. Mol. Biol. (2) Scientia Agricola (1) Autor Risso-Pascotto,Claudicéia (5) Pagliarini,Maria Suely (3) Valle,Cacilda Borges do (3) Godoy,Sara Mataroli de (2) Mendes-Bonato,Andréa Beatriz (2) Pereira,Andréia Rodrigues Alonso (2) Kiihl,Paulo Roberto Peres (1) Romagnolo,Mariza Barion (1) Stenzel,Neusa Maria Colauto (1) Mais... Palavra-chave Meiosis (3) Microsporogenesis (3) 2n gametes (2) Brachiaria (2) Chromosome number (2) Brachiaria jubata (1) Breeding program (1) Cell fusion (1) Euphorbiaceae (1) Forage grass (1) Interspecific hybridization (1) Meiotic rhythm (1) Pollen fertility (1) Polyploid (1) Polyploidy (1) Mais... Tipo do documento Info:eu-repo/semantics/article (5) Ano 2012 (1) 2011 (1) 2009 (1) 2006 (1) 2003 (1) País Brazil (5) Idioma Inglês (5)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 5 Primeira ... 1 ... Última Cytogenetic evidence for genome elimination during microsporogenesis in interspecific hybrid between Brachiaria ruziziensis and B. brizantha (Poaceae) Genet. Mol. Biol. Mendes-Bonato,Andréa Beatriz; Risso-Pascotto,Claudicéia; Pagliarini,Maria Suely; Valle,Cacilda Borges do. Microsporogenesis was analyzed in an interspecific hybrid between an artificially tetraploidized sexual accession of Brachiaria ruziziensis (R genome) and a natural apomictic tetraploid accession of B. brizantha (B genome). Chromosomes associated predominantly as bivalents. From this phase to the end of meiosis, chromosomes presented irregular segregation and abnormal arrangement in the metaphase plate. During metaphase I, in 27.8% of meiocytes, bivalents were distributed in two metaphase plates. In anaphase I, two distinct and typical bipolar spindles were formed. In 29.7% of pollen mother cells, one genome did not divide synchronically, with chromosomes lagging behind or not segregating at all. The second division was very irregular, resulting in... Tipo: Info:eu-repo/semantics/article Palavras-chave: Brachiaria; Forage grass; Interspecific hybridization; Meiotic rhythm; Microsporogenesis. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000400021 Normal microspore production after cell fusion in Brachiaria jubata (Gramineae) Genet. Mol. Biol. Mendes-Bonato,Andréa Beatriz; Risso-Pascotto,Claudicéia; Pagliarini,Maria Suely; Valle,Cacilda Borges do. Cytogenetic studies were carried out on 22 accessions of Brachiaria jubata from the Embrapa Beef Cattle Brachiaria collection. One accession was diploid (2n = 2x = 18) and the remaining 21 were tetraploid (2n = 4x = 36). Among five tetraploid accessions, a specific and constant pattern of cell fusion involving only two microsporocytes was recorded. Meiosis proceeded normally from prophase I to the end, giving rise to an octad with normal microspores that developed into fertile pollen grains. Regular octad formation was possible because each cellular chromosome set was maintained in its proper domain, spindles were correctly positioned, and cytokinesis planes were formed in the correct places. Such behavior of meiosis in syncytes has never been reported in... Tipo: Info:eu-repo/semantics/article Palavras-chave: Brachiaria jubata; Cell fusion; Microsporogenesis; Pollen fertility. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000400016 Microsporogenesis in Brachiaria bovonei (Chiov.) Robyns and B. subulifolia (Mez) Clayton (Poaceae) Scientia Agricola Risso-Pascotto,Claudicéia; Pagliarini,Maria Suely; Valle,Cacilda Borges do. Some African species of Brachiaria have been introduced into the Americas and became the most important forage for pastures in the tropics. New cultivars can be obtained either from direct selections from the natural existing variability in the germplasm collections or from interspecific hybridizations. Polyploidy is predominant in the genus Brachiaria and correlated with apomixis which complicates hybridization. The objective of cytological studies underway on the Brachiaria germplasm collection at Embrapa Beef Cattle is to determine the chromosome number and meiotic behavior of accessions. For the breeding of Brachiaria species, compatible sexual and apomictic accessions need to be identified. Microsporogenesis was evaluated in two accessions of... Tipo: Info:eu-repo/semantics/article Palavras-chave: Brachiaria; Meiosis; Chromosome number; Polyploidy; Breeding program. Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000500015 Chromosome stickiness during meiotic behavior analysis of Passiflora serrato-digitata L. (PassifloraCEAE) Ciência Rural Kiihl,Paulo Roberto Peres; Pereira,Andréia Rodrigues Alonso; Godoy,Sara Mataroli de; Stenzel,Neusa Maria Colauto; Risso-Pascotto,Claudicéia. Almost 90% of species of the genus Passiflora are native to the American continent, with high commercial value due to the fact that some species are used for human food while others have ornamental and medical qualities. Passiflora serrato-digitata is one of the species that integrates the Paraná Agronomic Institute germoplasm bank at its experimental base in Londrina, PR, Brazil. Collected flower buds were fixed in ethanol/acetic acid (3:1 v/v) for 24h, transferred to 70% alcohol and stored under refrigeration. Slides were prepared by the squashing technique and stained with 1.0% propionic carmine; they were analyzed under an optic microscope. Irregularities in the chromosome segregation process of P. serrato-digitata have been verified by meiotic... Tipo: Info:eu-repo/semantics/article Palavras-chave: Microsporogenesis; Meiosis; 2n gametes. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782011000600016 Meiotic behavior during microsporogenesis of Alchornea triplinervia (Sprengel) Müller Argoviensis Ciência Rural Godoy,Sara Mataroli de; Pereira,Andréia Rodrigues Alonso; Romagnolo,Mariza Barion; Risso-Pascotto,Claudicéia. The Alchornea triplinervia specie belongs to the Euphorbiaceae family, one of the main families of the Brazilian flora. In order to contribute to a better understanding of the specie, a counting of chromosome number and the microsporogenesis analysis of A. triplinervia were done. The inflorescences were collected in the municipalities of Paranavaí and Diamante do Norte, State of Paraná, Brazil, and the slides were prepared by squashing technique and staining with 1% acetic carmine. The analysis were performed using an optical microscope and showed a chromosome number for the specie equal to 2n=8x=72. Irregularities in the chromosome segregation process were the main meiotic abnormalities, presenting typical polyploid behavior. Other irregularities were... Tipo: Info:eu-repo/semantics/article Palavras-chave: Euphorbiaceae; Chromosome number; 2n gametes; Meiosis; Polyploid. Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782012000600012 Registros recuperados: 5 Primeira ... 1 ... Última

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