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Registros recuperados: 77 | |
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Briones Reyes, Dolores. |
Con el objeto de evaluar la resistencia genética a la pudrición de la mazorca de nueve ciclos de selección de cada una de tres poblaciones de maíz Chalqueño (Azul, Palomo y Crema), y de determinar la distribución y virulencia de las especies de hongos causantes de la pudrición, se colectaron 26 muestras de mazorcas con y sin síntomas de pudrición en tres zonas de los Estados de México, Tlaxcala y Puebla. La evaluación de la resistencia se hizo en tres localidades, utilizando la mezcla de 15 aislamientos colectados en la región Chalco-Juchitepec, que fueron inoculados en los jilotes entre 7 y 10 días después de la emisión de los estigmas. La severidad de la enfermedad se evaluó a la cosecha, utilizando la escala 1 a 5 de acuerdo al porcentaje de infección.... |
Tipo: Tesis |
Palavras-chave: Ciclos de selección; Fusarium; Resistencia genética; Pudrición de mazorca; Virulencia; Maestría; Genética; Selection cycles; Genetic resistance; Ear rot; Virulence. |
Ano: 2007 |
URL: http://hdl.handle.net/10521/1660 |
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Briones Reyes, Dolores. |
Las variantes de maíz (Zea mays L.) nativas (criollos) preservadas por los agricultores a través de generaciones, constituyen más de 80% del área sembrada con maíz en México; la pudrición de mazorca por Fusarium spp. provoca pérdidas de hasta 30%. El estudio de las poblaciones de maíz y sus patógenos como patosistema tiene sentido, pues en la variación genética del maíz nativo se puede encontrar resistencia/tolerancia a enfermedades; el conocimiento de la estructura de las poblaciones de maíz y del patógeno de manera integral ayudaría a resolver el problema de pudrición, aumentar la producción de grano y conservar la diversidad del maíz. En 2010 se colectaron 56 poblaciones de maíz nativo con y sin síntomas de pudrición de mazorca en cinco estados en... |
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Palavras-chave: Diversidad; Patosistema; Fusarium spp.; Maíz nativo; Pudrición de mazorca; Virulencia; Diversity; Pathosystem; Native maize; Ear rot; Virulence; Genética; Doctorado. |
Ano: 2013 |
URL: http://hdl.handle.net/10521/2163 |
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Aggarwal,Rashmi; Kulshreshtha,Deepika; Sharma,Sapna; Singh,Vaibhav K.; Manjunatha,Channappa; Bhardwaj,Subhash C.; Saharan,Mahender S.. |
Abstract Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is one of the most devastating diseases of wheat (Triticum spp.) worldwide. Indian isolates were characterised based on their phenotypic reaction on differential hosts carrying different Yr genes. Based on virulence/avirulence structure, isolates were characterised into ten different pathotypes viz. 70S0-2, 67S64, 70S4, 66S0, 70S64, 66S64-1, 38S102, 47S102, 46S119, and 78S84. These Indian pathotypes of P. striiformis f. sp. tritici and 38 pathotypes of other rust species (P. graminis tritici and P. triticina) were used in this study to analyze their molecular phylogenetic relationship. The nucleotides of rDNA-ITS, partial β-tubulin and ketopantoate reductase genes of all the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Wheat; Stripe rust; Virulence; Diversity; Phylogeny. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000500834 |
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GASPAROTTO, L.; FERREIRA, F. A.. |
Mal-das-folhas da seringueira: historico de ocorrencias e importancia economica, distribuicao geografica e hospedeiros. Microcyclus ulei: sintomatologia, isolamento, caracteristicas culturais e morfologicas, patogenicidade, variabilidade para virulencia a Hevea spp. e para resistencia ao mal-das-folhas. Ciclo do mal-das-folhas. Epidemiologia do mal-das-folhas. Controle: areas de escape, fungicidas, resistencia da planta, enxertia de copa. |
Tipo: Capítulo em livro técnico (INFOTECA-E) |
Palavras-chave: Mal-das-folhas; SALB; Morfologia; Ciclo; Virulencia; Brasil; Rubber tree; Fungal diseases; South American leaf blight; Geographic distribution; Host; Symptoms; Isolation methods; Morphology; Cicle; Resistance; Controle Químico; Distribuição Geográfica; Doença; Epidemiologia; Espécie; Folha; Fungo; Hevea; Hospedeiro; Isolamento; Microcyclus Ulei; Patogenicidade; Resistência; Seringueira; Sintoma; Chemical control; Epidemiology; Leaves; Pathogenicity; Virulence. |
Ano: 1989 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/667342 |
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ROSINHA, G. M. S.; MELO, P. R. de; SANTOS, L. R. dos; CARVALHO, C. E. G.; ALVARENGA, L. C. O.; ANDRADE, G. B.; SOARES, C. O.. |
Corynebacterium pseudotuberculosis é uma bactéria Gram-positiva, agente etiológico da linfadenite caseosa (LC) em pequenos ruminantes e causadora de piogranulomas, linfangite ulcerativa, mastite e dermatite ulcerativa em bovinos, que são doenças de grande relevância médica e veterinária. Esta doença é de difícil controle e a vacinação é a maneira mais eficiente de preveni-la nos rebanhos. Objetivou-se neste estudo selecionar cepas virulentas de C. pseudotuberculosis, a partir de cinco isolados obtidos de caprinos e ovinos, para uso em estudos de desafio em testes de novas vacinas contra linfadenite caseosa em camundongos. Primeiramente, os isolados foram caracterizados bioquimicamente com o kit API Coryne (APIbioMerieux, Inc., La Balme les Grottes, France)... |
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Corynebacterium Pseudotuberculosis; Histopatologia; Linfadenite Caseosa; Patogenicidade; Caseous lymphadenitis; Virulence; Histopathology. |
Ano: 2018 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1106896 |
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Gay, Melanie; Berthe, Franck; Leroux, Frederique. |
In an attempt to develop a reproducible experimental model of bacterial infection in Crassostrea gigas, oysters taken from very localised sub-populations suffering natural mortality outbreaks were used in cohabitation trials under laboratory conditions. From these trials, a collection of Vibrio strains was isolated from moribund and healthy oysters. In a second step, strains were experimentally tested for virulence by means of injection into healthy oysters. This screening revealed a span of virulence among isolated strains from none to medium. When pooling injected strains, results suggest increased virulence. Vibrio strains may have additive/synergistic action leading to higher C, gigas mortality rates in experimental challenges. Although the study... |
Tipo: Text |
Palavras-chave: Crassostrea gias; Antagonism; Agonism; Virulence; Vibrio splendidus. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-3174.pdf |
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Goarant, Cyrille; Reynaud, Yann; Ansquer, Dominique; De Decker, Sophie; Saulnier, Denis; Leroux, Frederique. |
A collection of 57 isolates of Vibrio nigripulchritudo from either diseased or healthy shrimp and from shrimp farms environment was studied in order to gain a better understanding of the epidemiology of this pathogen, notably isolated from two distinct shrimp disease complexes. Molecular typing using two different techniques, arbitrarily primed PCR (AP-PCR) and multi-locus sequence typing (MLST), studied together with experimental pathology data allowed a relevant epidemiological insight into this possibly emerging pathogen. Additionally, results obtained with the two molecular typing techniques were congruent and allowed discriminating the strains associated with the "Summer Syndrome" from strains isolated from other contexts, especially the other shrimp... |
Tipo: Text |
Palavras-chave: Virulence; Epidemiology; Typing; MLST; AP PCR; Mariculture; Vibriosis. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1913.pdf |
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Travers, Marie-agnes; Degremont, Lionel; De Lorgeril, Julien; Azema, Patrick; Montagnani, Caroline; Benabdelmouna, Abdellah; Nicolas, Jean-louis; Le Roux, Frederique. |
En 2012, le nombre de cas de mortalités d’huîtres creuses adultes rapportés dans le cadre du réseau Repamo, et dans lesquels la bactérie Vibrio aestuarianus a été isolée, a fortement augmenté. Afin d’apporter de premiers éléments de réponse concernant cette augmentation, les objectifs de cette étude étaient de déterminer si l’émergence/la ré-émergence de V. aestuarianus était associée (i) à l’apparition d’un génotype bactérien particulier et/ou (ii) à une sensibilité accrue de certains animaux. L’Ifremer dispose d’une collection de souches bactériennes appartenant majoritairement au genre Vibrio et qui comporte différents isolats de V. aestuarianus, collectés depuis 2001 pendant ou hors épisodes de mortalité. La comparaison de ces isolats en termes de... |
Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Huître creuse; Crassostrea gigas; Bactérie; Ré-émergenece; Virulence; Génome; Statut immunitaire; Génétique. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00229/34037/32430.pdf |
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Rodrigues, Sophie; Paillard, Christine; Van Dillen, Sabine; Tahrioui, Ali; Berjeaud, Jean-marc; Dufour, Alain; Bazire, Alexis. |
Marine pathogenic bacteria are able to form biofilms on many surfaces, such as mollusc shells, and they can wait for the appropriate opportunity to induce their virulence. Vibrio tapetis can develop such biofilms on the inner surface of shells of the Ruditapes philippinarum clam, leading to the formation of a brown conchiolin deposit in the form of a ring, hence the name of the disease: Brown Ring Disease. The virulence of V. tapetis is presumed to be related to its capacity to form biofilms, but the link has never been clearly established at the physiological or genetic level. In the present study, we used RNA-seq analysis to identify biofilm- and virulence-related genes displaying altered expression in biofilms compared to the planktonic condition. A... |
Tipo: Text |
Palavras-chave: Biofilm; Virulence; Vibrio tapetis; Transcriptome; Quorum sensing; Type VI secretion system; Brown ring disease. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58140/60611.pdf |
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Le Roux, Frédérique; Gay, Melanie; Lambert, Christian; Waechter, Magali; Poubalanne, Saravanne; Chollet, Bruno; Nicolas, Jean-louis; Berthe, Franck. |
French mollusc production is based mainly on the Pacific cupped oyster, Crassostrea gigas. Since 1991, annual mass mortality of juveniles has been reported during summer months. These recurring episodes concern professionals who fear that like Portugese oyster, C. angulata, C gigas could in turn disappear following one of these epizooties. Previously, bacteriological analysis of moribund oyster juveniles yielded an isolate of a Vibrio splendidus biovar H strain, named TNEMF6. This isolate was demonstrated to be pathogenic to Crassostrea gigas spat by experimental challenge. To study the association between summer oyster mortality and presence of TNEMF6 cluster strains, Vibrionaceae fauna were isolated from infected spat along the French Atlantic coast... |
Tipo: Text |
Palavras-chave: Vibrio splendidus; Virulence; Epidemiology; PCR RFLP; Oyster mortality. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-565.pdf |
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De Decker, Sophie. |
The bacteria of the Vibrio genus are one of the most abundant groups in the aquatic ecosystems. Two species of vibrios, Vibrio splendidus and V. Aestuarianus, have been associated, in some cases, to mortality in flat oyster Crassostrea gigas farms, most of the time during the summer period. This doctoral thesis studies the Vibrio-host interaction and their modulations according to the host's pathogenic virulence and its genetic, physiologic and immunitary parameters. These factors will be characterised by in vitro and in vivo approaches (experimental infection). The characterization of contrasted genetic families according to their sensitivity to these vibrios will enable the implementation of new improvement strategies in oyster farms (prophylactic... |
Tipo: Text |
Palavras-chave: Immunologie; Physiologie; Paramètres génétiques; Virulence; Oyster; Crassostrea gigas; Pathogène; Vibrio. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3431.pdf |
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Goudenege, David; Labreuche, Yannick; Krin, Evelyne; Ansquer, Dominique; Mangenot, Sophie; Calteau, Alexandra; Medigue, Claudine; Mazel, Didier; Polz, Martin F.; Le Roux, Frederique. |
Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively... |
Tipo: Text |
Palavras-chave: Horizontal gene transfer; Nigritoxin; Phylogeny; Shrimp; Virulence; Vibrio. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27117/28369.pdf |
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Baleux, B; Caro, A; Lesne, J; Got, P; Binard, S; Delpeuch, B. |
The release of enteric pathogenic bacteria in aquatic environments poses the problem of the fate of these bacteria under the effects of environmental factors (solar radiation, salt concentration, temperature, nutrient level, pH, competition). Frequently, these bacterial cells, potentially pathogenic, enter into a non-culturable state on routine bacteriological plating media. However, the use of direct detection methods (DAPI stained cells) allows the visualization of these Viable but Non Culturable cells (VNC). But, beyond the characterization of the viability of the cells (electron transport activity, metabolic activity, membrane integrity, structure and/or quantity of DNA), what happens with the virulence of these cells? This problem was experimentally... |
Tipo: Text |
Palavras-chave: Salmonella; Survie; Virulence; VNC; Stress; Salmonella; Survival; Virulence; VNC; Stress. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43645/43245.pdf |
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Le Roux, Frederique. |
Global changes linked to increases in temperature and ocean acidification, but also to more direct anthropogenic influences such as aquaculture, have caused a worldwide increase in the reports of Vibrio-associated illnesses affecting humans and also animals such as shrimp and molluscs. Investigation of the emergence of Vibrio pathogenesis events requires the analysis of microbial evolution at the gene, genome and population levels, in order to identify genomic modifications linked to increased virulence, resistance and/or prevalence, or to recent host shift. From a more applied point of view, the elucidation of virulence mechanisms is a prerequisite to devising prophylactic methods to fight infectious agents. In comparison with human pathogens, fairly... |
Tipo: Text |
Palavras-chave: Écologie; Émergence; Évolution; Invertébrés marins; Vibriose; Virulence; Ecology; Emergence; Evolution; Marine invertebrate; Vibriosis; Virulence. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00344/45560/46722.pdf |
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Registros recuperados: 77 | |
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