Consulta: creatorFacets:"Techio,Vânia Helena"
Registros recuperados: 12
Data/hora: 29/05/2024 05:37:48

Cytotaxonomy of some species and of interspecific hybrids of Pennisetum (Poaceae, Poales)
Provedor de dados: 74
Autores: Techio,Vânia Helena; Davide,Lisete Chamma; Pereira,Antônio Vander; Bearzoti,Eduardo.
Cytotaxonomic studies were carried out on 26 accessions of Pennisetum spp. originating from the Active Germplasm Bank of Embrapa Gado de Leite-Juiz de Fora, Minas Gerais, Brazil.This study presents cytogenetics and reproductive morphological data for each one of these accessions, which allowed groupings and suggest botanical identifications to be established. The metaphases of the accessions characterized as P. purpureum confirmed the presence of 2n = 28 chromosomes that have already been described for this species. For the hybrids between P. purpureum and P. glaucum and for the hexaploids, resulting from the chromosome duplication of these hybrids, 2n = 21 and 2n = 42 chromosomes were confirmed, respectively. The wild accession identified as P. setosum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pennisetum; Cytogenetic; Taxonomy; Germplasm; Genetic divergence.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000200014

Meiosis in elephant grass (Pennisetum purpureum), pearl millet (Pennisetum glaucum) (Poaceae, Poales) and their interspecific hybrids
Provedor de dados: 74
Autores: Techio,Vânia Helena; Davide,Lisete Chamma; Pereira,Antônio Vander.
The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28) and Pennisetum glaucum (pearl millet, 2n = 2x = 14) can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these species is infertility due to triploidy (2n = 3x = 21). This study describes meiosis in elephant grass x pearl millet hybrids and their progenitors. Panicles were prepared according to the conventional protocol for meiotic studies and Alexander’s stain was used for assessing pollen viability. Pearl millet accessions presented regular meiosis with seven bivalents and high pollen viability. For elephant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Meiosis; Pennisetum; Elephant grass; Interspecific hybrids; Pearl millet; Pollen.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000200025

Intra- and intergenomic chromosomal pairing in artificially polyploidized elephant grass and pearl millet hybrids
Provedor de dados: 86
Autores: Santos,Fernanda Motta da Costa; Torres,Giovana Augusta; Techio,Vânia Helena; Pereira,Antônio Vander; Davide,Lisete Chamma.
Abstract: The objective of this work was to evaluate, by genomic in situ hybridization (GISH), pairing configurations as potential indicators of recombination between chromosomes of different parental genomes, in two interspecific hybrids (elephant grass x pearl millet) artificially polyploidized. Anthers from young flower buds were used in the chromosomal preparations. The genomic probe was prepared with pearl millet DNA and labeled with biotin-16-dUTP by the nick translation reaction. Blocking DNA was prepared with genomic elephant grass DNA. The homoeologous intergenomic pairing, observed in the two hybrids, indicates the possibility of recombination between chromosomes of the parental genomes.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pennisetum glaucum; Pennisetum purpureum; In situ hybridization; Intergenomic pairing; Interspecific hybridization.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017000900814

Número cromossômico e conteúdo de DNA nuclear em espécies do gênero Amaranthus (Amaranthaceae)
Provedor de dados: 86
Autores: Samartini,Carolina Queiroz; Resende,Luciane Vilela; Techio,Vânia Helena; Braz,Guilherme Tomaz; Silva,Luis Felipe Lima e; Resende,Kátia Ferreira Marques de.
Resumo: O objetivo deste trabalho foi determinar o número de cromossomos e o conteúdo de DNA nuclear em cinco espécies do gênero Amaranthus, de ocorrência comum no Brasil. Cromossomos metafásicos foram obtidos pela técnica de secagem à chama e corados com Giemsa 5%, e o conteúdo de DNA foi determinado por citometria de fluxo. Observou-se 2n=32 cromossomos em A. hybridus e 2n=34 nas demais espécies estudadas, o que é indicativo de ocorrência de disploidia descendente. O conteúdo de DNA nuclear variou de 1,28 a 1,79 pg, e A. deflexus apresentou o maior valor.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Caruru; Citogenética; Disploidia; Variabilidade genética.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000800998

Karyotipic asymmetry of both wild and cultivated species of Pennisetum
Provedor de dados: 53
Autores: Techio,Vânia Helena; Davide,Lisete Chamma; Cagliari,Alexandro; Barbosa,Sandro; Pereira,Antônio Vander.
This study aimed the establishment of the relation between karyotipic asymmetry values obtained for different accessions of both wild and cultivated species of Pennisetum from Germplasm Bank of Embrapa Gado de Leite/Juiz de Fora-Minas Gerais State, Brazil. Conventional cell cycle synchronization protocols and Feulgen staining method were used to obtain metaphases plates. The wild-type accessions corresponded to the species P. setosum (2n=6x=54), P. nervosum (2n=4x=36), and P. orientale (2n=4x=36), and the cultivated to P. purpureum (2n=4x=28) and P. glaucum (2n=2x=14). No significant difference was found for the total length of chromosomes (p&gt;0.05) among the species. The analysis of intra-chromosomal asymmetry (A1) and inter-chromosomal asymmetry (A2)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pennisetum purpureum; Pennisetum glaucum; Germplasm; Karyotype.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000200003

Stability in chromosome number and DNA content in synthetic tetraploids of  Lolium multiflorum after two generations of selection
Provedor de dados: 65
Autores: Pereira,Roselaine Cristina; Santos,Natália de Souza; Bustamante,Fernanda de Oliveira; Mittelmann,Andrea; Techio,Vânia Helena.
ABSTRACT: Chromosome doubling of Italian ryegrass genotypes ( Lolium multiflorum Lam.) adapted to the brazilian edaphoclimatic conditions is an important strategy used by breeders and aims to obtain more vigorous genotypes with better forage quality and disease resistance. The effectiveness of chromosome doubling can be measured by genetic stability and fertility rates of plants over generations. However, a common problem in the polyploidization process is the regeneration of mixoploid plants that have impaired fertility and genetic stability. The objective of this study was to verify if progenies of recently tetraploidized plants remain stable regarding DNA content and chromosome number, over two generations. Progenies of L. multiflorum plants...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chromosomal duplication; Mixoploidy; Italian ryegrass; Plant breeding.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782017000200401

Meiotic and mitotic behaviour of B chromosomes of ryegrass
Provedor de dados: 65
Autores: Techio,Vânia Helena; Mittelmann,Andréa; Marció,Simone; Pereira,Antônio Vander.
Mitotic and meiotic analyses using conventional and fluorescent stains were employed in plants (accession ETBAZ 055 - origin: Capão do Leão, Rio Grande do Sul State, Brazil) from the Germplasm Active Bank of Ryegrass (Banco Ativo de Germoplasma de Azevém) of Embrapa, for observing the behaviour of B chromosomes. In several meiotic stages, there were observed up to two B chromosomes, which have presented an unstable behaviour regarding their precocious ascension to metaphase I or delays during anaphase I. At the end of the process, the Bs showed predominantly segregation for the nuclei under formation in order to guarantee their propagation. Concerning the cells that comprise the anther tapetum and the root meristems, the B chromosomes have presented a more...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lolium multiflorum; Accessory chromosome; Preferential segregation.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782010000100014

Antibacterial activity of vegetal extracts against serovars of Salmonella
Provedor de dados: 65
Autores: Voss-Rech,Daiane; Klein,Cátia Silene; Techio,Vânia Helena; Scheuermann,Gerson Neudi; Rech,Gilberto; Fiorentin,Laurimar.
in vitro antibacterial activity of 21 hydroethanolic vegetal extracts was assessed against 20 serovars of Salmonella. Regarding the tested extracts, 85.7% of them presented antibacterial activity. The six active extracts which showed activity on the largest number of serovars and the extract of Eucalyptus sp. were submitted to the determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Of these, six extracts showed bacteriostatic and bactericidal activity with MIC and MBC for Punica granatum (pomegranate) from 20 and 60mg mL-1, for Eugenia jambolana (rose apple) from 40 and 240mg mL-1, Eugenia uniflora (surinam cherry) from 80 and 240mg mL-1, Caryophyllus aromaticus (clove) from 10 and 60mg mL-1, Psidium araca...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antibacterial activity; Vegetal extracts; Salmonella.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782011000200022

Forage potential of Urochloa genotypes by using leaf anatomy
Provedor de dados: 65
Autores: Mauri,Janaína; Pereira,Daniele Laís; Silva,Gabrielle Avelar; Davide,Lisete Chamma; Techio,Vânia Helena; Souza Sobrinho,Fausto; Pereira,Fabricio José.
ABSTRACT:  The digestibility potential of leaves from forages depends on the amount of nutrition in their tissues, with low lignin deposition in the cell wall, mainly parenchyma and phloem. This research evaluated the leaf structure of different Urochloa genotypes and discussed its potential for evaluating digestibility. The cultivars U. brizantha, U. decumbens, U. ruziziensis and three clones of U. ruziziensis (1, 95 and 97), which are under development in breeding programs, were evaluated. Plants were grown under the recommended culture conditions for the Urochloa species. Plants were cut 60 days after sowing, and leaves were collected at 15 days of regrowth. Leaves were fixed in FAA 70 and further stored in 70% ethanol until being submitted to the usual...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digestibility; Forage production; Leaf anatomy; Sclerenchyma; Lignin.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000400401

Duplicação cromossômica de gramíneas forrageiras: uma alternativa para programas de melhoramento genético
Provedor de dados: 65
Autores: Pereira,Roselaine Cristina; Davide,Lisete Chamma; Techio,Vânia Helena; Timbó,Ana Luiza Oliveira.
A obtenção artificial de genótipos com duplicação cromossômica em forrageiras busca maximizar características de interesse agronômico, como valor nutricional e produção de forragem, resistência a pragas e doenças, tolerância a estresses abióticos e restauração da fertilidade de híbridos estéreis. Outro objetivo da duplicação cromossômica é a geração de variabilidade genética em espécies apomíticas, por meio da duplicação cromossômica de acessos sexuais igualando a ploidia de modo a permitir a realização de cruzamentos e a obtenção de descendentes férteis. A indução de poliploidia é feita utilizando substâncias antimitóticas, sendo a colchicina a mais amplamente usada em plantas forrageiras. Entretanto, devido a sua toxicidade, outras substâncias como...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Poliploidização; Substâncias antimitóticas; Colchicina; Herbicidas; Cafeína; Explantes.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782012000700023

Morphology and pollen viability of Lolium multiflorum Lam.
Provedor de dados: 64
Autores: Nunes,Renata de Castro; Bustamante,Fernanda de Oliveira; Techio,Vânia Helena; Mittelmann,Andréa.
Study and characterization of pollen grains are essential for different areas, especially taxonomy, genetic improvement, phylogeny, and paleobotany. As yet, there are no reports on pollen morphology of genotypes of naturalized Lolium multiflorum Lam., introduced cultivars or breeding populations, diploid or polyploid. Ten genotypes of annual ryegrass (L. multiflorum) were evaluated for the viability of pollen grains using propionic carmine and Alexander's stains, while morphology was assessed by the acetolysis technique. Measures of polar axis (P), equatorial diameter (E), exine thickness, and analysis of pollen grains were obtained by scanning electron microscopy (SEM). All genotypes showed high rate of pollen viability (&gt; 89%) for both stains. There...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Scanning electron microscopy; Ryegrass; Acetolysis.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542012000200006

Variação cromossômica numérica em Pennisetum
Provedor de dados: 64
Autores: Davide,Lisete Chamma; Techio,Vânia Helena; Nunes,Juliane Dornellas; Pereira,Antônio Vander.
Entre os acessos de Pennisetum da Coleção de Germoplasma da Embrapa Gado de Leite - Juiz de Fora, MG, avaliados em estudos anteriores, o BAG 55, capim-elefante cv. Kizozi, introduzido do Estado da Bahia e cuja origem genealógica é desconhecida, apresentou variação cromossômica numérica (2n=54 a 66 cromossomos) em diversas contagens, embora a sua identificação no Banco de Germoplasma como P. purpureum Schum. sugerisse que o mesmo apresentasse 2n=28 cromossomos. Neste estudo foram feitas análises mitóticas comparativas entre este acesso com outros quatro representantes de capim-elefante (P. purpureum) e foram obtidas medições cromossômicas. Para o acesso BAG 55 também foram realizadas análises meióticas e de viabilidade de pólen. Os resultados das análises...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pennisetum; Citogenética; Variação cromossômica numérica.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542007000200020