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Search Results: 1 - 10 of 564352 matches for " William Mário de Carvalho;Scapim "
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Nonlinear models for describing the Citrus Variegated Chlorosis in groves of two counties at northwestern Paraná state, Brazil = Modelo n o-linear para a curva de progresso de incidência da Clorose Variegada dos Citros (CVC) em dois municípios da regi o noroeste do Estado do Paraná
Clara Matiko Ueda,Akemi Yamagata Yamamoto,William Mário de Carvalho Nunes,Carlos Alberto Scapim
Acta Scientiarum : Agronomy , 2010,
Abstract: In Brazil, the production of sweet oranges has been threatened by the Citrus Variegated Chlorosis (CVC) incited by the gram-negative bacterium Xylella fastidiosa (Wells). Commercial citrus groves in two counties at the Northwestern Paraná state were evaluated to estimate the disease progression by using parameterizations of nonlinear models. Groves of Citrus sinensis Osbeck, variety “Pêra”, “Valência”, “Natal” and “Folha Murcha” had all the plants evaluated for the presence of disease symptoms. Thereafter, different parameterizations of the Logistic and Gompertz models were fitted to these data. The goodness of fit was evaluated by the intrinsic (IN) and parameter-effects (PE) curvatures of Bates and Watts, the bias of Box and the Hougaard measures of skewness. In Loanda, the best model was the Fermi-Dirac, and in Nova Esperan a the data were best fitted to the parameterization L5, which is also a parameterization from the Logistic model. A citricultura é afetada por diversas doen as, dentre as quais a Clorose Variegada dos Citros (CVC) causada pela bactéria Xylella fastidiosa (Wells). Para a regi o noroeste do Estado do Paraná, onde foi avaliada a CVC, prop e-se encontrar modelos n o-lineares de curvas de progresso de incidência da CVC que representem o percentual de plantas acometidas pela doen a. Para avaliar o comprometimento dos pomares com rela o à doen a, foram escolhidos pomares comerciais em dois municípios, onde foi determinada a propor o de plantas doentes. Foram selecionados talh es de laranja doce (Citrus sinensis Osbeck) nas variedades “Pêra”, “Valência”, “Natal” e “Folha Murcha” e a avalia o de todas as plantas do talh o foi realizada visualmente em rela o à presen a ou à ausência de sintomas de CVC. Para estimar o modelo que melhor se ajustou aos dados de progresso da propor o da doen a em cada talh o, foram considerados modelos n o-lineares decrescimento sigmoidal, o logístico e o de Gompertz, conforme sugerido na literatura. A escolha do melhor modelo foi com base em medidas de curvatura intrínseca e paramétrica de Bates e Watts, viés de Box e medida de assimetria de Hougaard. O modelo que melhor ajustou aos dados de Loanda foi o modelo de Fermi-Dirac e aos dados de Nova Esperan a foi outra reparametriza o do Modelo Logístico, denominado de L5.
Nonlinear models for describing the Citrus Variegated Chlorosis in groves of two counties at Northwestern Paraná State, Brazil
Ueda, Clara Matiko;Yamamoto, Akemi Yamagata;Nunes, William Mário de Carvalho;Scapim, Carlos Alberto;Guedes, Terezinha Aparecida;
Acta Scientiarum. Agronomy , 2010, DOI: 10.4025/actasciagron.v32i4.11625
Abstract: in brazil, the production of sweet oranges has been threatened by the citrus variegated chlorosis (cvc) incited by the gram-negative bacterium xylella fastidiosa (wells). commercial citrus groves in two counties at the northwestern paraná state were evaluated to estimate the disease progression by using parameterizations of nonlinear models. groves of citrus sinensis osbeck, variety "pêra", "valência", "natal" and "folha murcha" had all the plants evaluated for the presence of disease symptoms. thereafter, different parameterizations of the logistic and gompertz models were fitted to these data. the goodness of fit was evaluated by the intrinsic (in) and parameter-effects (pe) curvatures of bates and watts, the bias of box and the hougaard measures of skewness. in loanda, the best model was the fermi-dirac, and in nova esperan?a the data were best fitted to the parameterization l5, which is also a parameterization from the logistic model.
Stability of Citrus tristeza virus protective isolates in field conditions
Costa, Alessandra Tenório;Nunes, William Mário de Carvalho;Zanutto, Carlos Alexandre;Müller, Gerd Walter;
Pesquisa Agropecuária Brasileira , 2010, DOI: 10.1590/S0100-204X2010000700009
Abstract: the objective of this work was to monitor the maintenance of citrus tristeza virus (ctv) protective isolates stability in selected clones of 'pêra' sweet orange (citrus sinensis), preimmunized or naturally infected by the virus, after successive clonal propagations. the work was carried out in field conditions in the north of paraná state, brazil. coat protein gene (cpg) analysis of 33 isolates collected from 16 clones of 'pêra' sweet orange was performed using single strand conformational polymorphism (sscp). initially, the isolates were characterized by symptoms of stem pitting observed in clones. then viral genome was extracted and used as template for the amplification of cpg by reverse transcription polimerase chain reaction (rtpcr). rtpcr products electrophoretic profiles were analyzed using the jaccard coefficient and the upgma method. the majority of the clones had weak to moderate stem pitting symptoms and its ctv isolates showed alterations in the sscp profiles. however, the stability of the protective complex has been maintained, except for isolates from two analised clones. low genetic variability was observed within the isolates during the studied years.
Populational fluctuation of vectors of Xylella fastidiosa, wells in sweet orange [Citrus sinensis (L.) Osbeck] varieties of northwest Paraná State, Brazil
Molina, Rúbia de Oliveira;Gon?alves, Aline Maria Orbolato;Zanutto, Carlos Alexandre;Nunes, William Mário de Carvalho;
Brazilian Archives of Biology and Technology , 2010, DOI: 10.1590/S1516-89132010000300007
Abstract: the aim of the present study was to assess the population flutuation of the sharpshooters species subfamily cicadellinae belonging to the tribes cicadellini and proconiini, in sweet orange [citrus sinensis( l). osbeck] commercial orchards of the northwest region of paraná state , brazil. samplings were carried out the employing every time 24 yellow sticky cards. identification of the species showed that the most representative were dilobopterus costalimai of the cicadellini tribe and acrogonia citrina of the proconiini tribe.
Análise espa o-temporal da clorose variegada dos citros no Noroeste do Paraná, com uso de PCR para detec o de Xylella fastidiosa = Spatio-temporal analysis of the citrus variegated chlorosis (CVC) in the Northwest of Paraná, using PCR for detection of Xylella fastidiosa
William Mário de Carvalho Nunes,Carlos Alexandre Zanutto,Maria Júlia Corazza- Nunes,Rúbia de Oliveira Molina
Acta Scientiarum : Agronomy , 2006,
Abstract: A citricultura é afetada por inúmeras doen as, como a clorose variegada do citros (CVC), causada pela bactéria Xylella fastidiosa. O objetivo deste trabalho foi determinar a distribui o espacial da doen a dentro de pomares comerciais do Noroeste do Paraná com o uso de métodos moleculares. Foram selecionados pomares sintomáticos para CVC com as variedades ‘Pêra’, ‘Valência’ e ‘Folha Murcha’ (Citrus sinensis Osbeck). Foram marcadas para cada variedade, 4 plantas-referência positivas para CVC (por sintomas e análise molecular) e 8 plantas ao redor de cada uma das plantas-referência foram amostradas, num total de 36 plantas por variedade. Realizou-se o teste da Rea o da Polimerase em Cadeia (PCR) para detec o da bactéria e na mesma época foram conduzidas avalia es visuais de sintomas de CVC. Os resultados da análise temporal, utilizando-se os modelos Monomolecular, Logístico e Gompertz, apontaram o modelo Logístico como o que melhor se ajustou para descrever o comportamento da doen a no tempo, para todas as variedades estudadas. Observou-se que o comportamento espacial da doen a diferiu quando a mesma área foiavaliada pelos métodos visual e molecular, resultando em uma diferen a no padr o espacial das áreas avaliadas. Portanto, ambos os métodos empregados, sintomas e PCR, foram capazes de constatar asmudan as no padr o espacial apresentado, sendo que a análise molecular (PCR) foi mais sensível para detectar as mudan as ocorridas. Countless diseases affect the citriculture, as the citrus variegated chlorosis (CVC) which is caused by the bacteria Xylella fastidiosa.The aim of this work was to determine the space distribution of the disease inside commercial orchards in the Northwest of Paraná, using molecular methods. Symptomatic orchards were selected for CVC with the varieties 'Pêra', 'Valência' and 'Folha Murcha' (Citrus sinensis Osbeck). For each variety, 4 positive reference-plant for CVC (presence of CVC symptoms or molecular analysis by PCR) and 8 plants around of each one reference-plant were evaluated, totaling 36 plants for variety. The detection of the bacteria was conduced by Polimerase Chain Reaction (PCR) technique. Simultaneously, evaluations through visual symptoms of CVC were conducted. The results of the temporal analysis were obtained using the Monomolecular, Logistic and Gompertz models. The Logistic model was the one that best fit to describe the behavior of the disease in the time, for all the studied varieties. Data showed that the space behavior of the disease differed when the same area was evaluated by visual and molecular method
Incidência de Dilobopterus costalimai Young e Acrogonia citrina Marucci & Cavichioli, em pomares cítricos no noroeste paranaense = Incidence of Dilobopterus costalimai Young and Acrogonia citrina Marucci & Cavichioli, in citrus orchards in Northwestern Paraná
Aline Maria Orbolato Gon?alves,Rúbia de Oliveira Molina,William Mário de Carvalho Nunes,Carlos Alexandre Zanutto
Acta Scientiarum : Agronomy , 2008,
Abstract: As cigarrinhas das famílias Cicadellidae e Cercopidae s o vetores da bactéria Xylella fastidiosa Wells, causadora da Clorose variegada dos citros. Esta doen a traz sérios prejuízos à lavoura de citros no Noroeste Paranaense, e é estudada no Brasil desde 1987, quando foi descoberta pela primeira vez na regi o de Colina, S o Paulo. Os vetores transmitem a X. fastidiosa quando se alimentam sugando a seiva do xilema, local onde a bactéria se instala, obstruindo a passagem da seiva. Este trabalho teve o objetivo de avaliar aocorrência das cigarrinhas vetoras Dilobopterus costalimai e Acrogonia citrina em pomar comercial de citros. O experimento foi realizado no sítio “Laranjeiras I”, município de Nova Esperan a, regi o noroeste do Paraná, no período de julho de 2004 a agosto de 2006. Foram feitas amostragens mensais, por meio de armadilhas adesivas amarelas (Biocontrole ), nas variedades de laranjeiras [Citrus sinensis (L.) Osbeck] Folha Murcha, Valência, Pêra e Natal.Nas variedades Pêra e Valência, a cigarrinha mais capturada foi Dilobopterus costalimai. Os meses de maior ocorrência das espécies foram entre dezembro e maio de cada ano. The sharpshooters of the families Cicadellidae and Cercopidae are vectors of Xylella fastidiosa (Wells), which causes citrus variegated chlorosis. This disease causes severe damage to the Paraná citrus industry, and it has been studied in Brazil since 1987, when it was discovered for the first time in the area of Colina, SP. The vectors transmit X. fastidiosa when they feed on the xylem sap, where the bacteria settles, obstructing the passage of the sap. This workhad the objective of evaluating the occurrence of the vector sharpshooter Dilobopterus costalimai and Acrogonia citrina in a commercial citrus orchard during the period between July 2004 and August 2006. The experiment was accomplished in the Laranjeiras I farm, in the city of Nova Esperan a, northwestern Paraná. The collections were undertaken monthly, and yellow stick traps (Biocontrole ) was used as a sampling method in Folha murcha,Valência, Pêra and Natal oranges trees [Citrus sinensis (L.) Osbeck]. In Pêra and Valência trees, the most often captured sharpshooter was Dilobopterus costalimai. The months of higher occurrence of these species were between December and May of each year.
Acyl-lupeol esters from Parahancornia amapa (Apocynaceae)
Carvalho, Mário G. de;Velloso, Carlos R. X.;Braz-Filho, Raimundo;Costa, William F. da;
Journal of the Brazilian Chemical Society , 2001, DOI: 10.1590/S0103-50532001000400020
Abstract: from the roots of parahancornia amapa, family apocynaceae, the following compounds were isolated and identified nine new and ten known 3b-o-acyl lupeol esters, b-sitosterol, stigmasterol, b-sitosterone, the triterpenoids b-amyrin, a-amyrin, lupeol and their acetyl derivatives. the structures of these compounds were established by spectroscopic data, mainly 1h and 13c (hbbd and dept) nmr spectra. the methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by ms-gc analysis.
Acyl-lupeol esters from Parahancornia amapa (Apocynaceae)
Carvalho Mário G. de,Velloso Carlos R. X.,Braz-Filho Raimundo,Costa William F. da
Journal of the Brazilian Chemical Society , 2001,
Abstract: From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly 1H and 13C (HBBD and DEPT) NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by MS-GC analysis.
Caracteriza??o biológica e molecular de isolados do Citrus tristeza virus com potencial para utiliza??o em programas de pré-imuniza??o
Costa, Alessandra Tenório;Nunes, William Mário de Carvalho;Corazza, Maria Júlia;Zanutto, Carlos Alexandre;Müller, Gerd Walter;
Summa Phytopathologica , 2010, DOI: 10.1590/S0100-54052010000100014
Abstract: a cross-protection program citrus tristeza disease, caused by citrus tristeza virus (ctv) has been developed in the parana state, to obtain pera orange mother plants. thus, 20 plants were selected in the orange commercial fields of the north and northwest region. comparisons between mild and severe recognized isolates were made. the results showed mild-to-moderate stem pitting symptoms and the great majority of the isolates grouped up with the mild control isolate. these results suggest that the plants selected were infected by ctv mild haplotypes showing that they have mother plant potential.
Characterization of Citrus tristeza virus isolates from grapefruit (Citrus paradisi Macf.) accessions of Citrus Active Germplasm Bank
Corazza-Nunes, Maria Júlia;Machado, Marcos Antonio;Stach-Machado, Dagmar Ruth;Nunes, William Mário Carvalho;Carvalho, Sérgio Alves de;Müller, Gerd Walter;
Summa Phytopathologica , 2006, DOI: 10.1590/S0100-54052006000400002
Abstract: citrus tristeza virus (ctv) isolates from 35 grapefruit accessions belonging to citrus active germplasm bank of the "instituto agron?mico de campinas" located at the "centro apta citros sylvio moreira", cordeirópolis, s?o paulo state, brazil, were characterized and evaluated through symptoms in the trees, biological indexing, immunological diagnosis with different monoclonal antibodies and sscp analysis (single-strand conformation polymorphism) of the coat protein gene. symptomatology indicated that, in general, the group of plants with smaller canopy volume and severe stem pitting differed significantly from the group that presented greater vegetative development and mild to moderate stem pitting. however, the isolates from most of the accessions induced mild reaction on mexican lime. the serological evaluation through the das-elisa using monoclonal antibodies did not reveal any association between virus titer in the plant tissue and symptoms. the reaction with different monoclonal antibodies and the distinct electrophoresis patterns obtained through sscp showed that there is a high degree of diversity among the isolates that infect these grapefruit accessions. high complexity within the same isolate was also observed in the sscp profiles. this finding indicates that the ctv isolates from these plants are a complex mixture of ctv haplotypes. similar sscp banding patterns were observed among some plants with strong stem pitting symptoms, and among some plants with weak or moderate stem pitting symptoms.
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