Consulta: creatorFacets:"Lau,Douglas"
Registros recuperados: 8
Data/hora: 11/06/2024 05:25:56

Genetic control of Eucalyptus urophylla and E. grandis resistance to canker caused by Chrysoporthe cubensis
Provedor de dados: 74
Autores: Guimarães,Lúcio Mauro da Silva; Resende,Marcos Deon Vilela de; Lau,Douglas; Rosse,Leonardo Novaes; Alves,Alexandre Alonso; Alfenas,Acelino Couto.
Chrysophorte cubensis induced canker occurs in nearly all tropical and subtropical regions where eucalypts are planted, causing losses in both wood quality and volume productivity, especially so in the warmer and more humid regions of Brazil. The wide inter and intra-specific genetic variability of resistance to canker among Eucalyptus species facilitates the selection of resistant plants. In this study, we evaluated resistance to this pathogen in five Eucalyptus grandis (G) and 15 E. urophylla (U) trees, as well as in 495 individuals from 27 progenies derived from crosses between the trees. In the field, six-months-old test seedlings were inoculated with C. cubensis. Lesion length in the xylem and bark was measured eight months later. The results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Genetic resistance; Genetic breeding; Eucalypt and interspecific hybrids.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000300024

Occurrence of Aceria tosichella in Brazil
Provedor de dados: 86
Autores: Pereira,Paulo Roberto Valle da Silva; Navia,Denise; Salvadori,José Roberto; Lau,Douglas.
The objective of this work was to evaluate the occurrence of Aceria tosichella Keifer (Prostigmata: Eriophyidae), the wheat curl mite, in Rio Grande do Sul, Brazil. Samples to detect A. tosichella specimens were collected in wheat, corn, oat crops and potential host grasses in 46 localities, in October 2006, August and October 2007. Samples of wheat were also collected in experimental greenhouses at Embrapa Trigo, Passo Fundo, RS, Brazil. A. tosichella specimens were found in wheat samples from Passo Fundo, Palmeira das Missões, São Luís Gonzaga, and Santo Antônio das Missões, RS, Brazil. Symptoms due to A. tosichella infestations were observed only in greenhouse conditions. This is the first report of A. tosichella in Brazil and the second in South America.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Eriophyoidea; South America; Acari; Cereal; Quarantine; Virus.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000500015

Interception of Wheat mosaic virus (WMoV) in Brazil in maize seeds from the United States
Provedor de dados: 86
Autores: Botelho,Stephanie Regina Alves; Duarte,Macária Ferreira; Barbosa,Andreza Viveiros; Lau,Douglas; Sanches,Márcio Martinello; Fernandes,Fernanda Rausch.
Abstract: The objective of this work was to evaluate the phytosanitary aspect of two accessions of maize (Zea mays) seeds from the United States introduced to Brazil, regarding the presence of Wheat mosaic virus (WMoV). Two to three weeks after sowing, symptomatic leaves were tested by Elisa using specific antiserum to WMoV. The reaction was positive, and leaf samples were analyzed by real-time PCR and amplified PCR products were sequenced. The WMoV isolates had 99 to 100% nucleotide identity with isolates from Australia and the United States. Until now, there is no report of the presence of this virus in Brazil. According to the federal law on plant protection, the plants were burned to avoid the introduction of this exotic pest in the country. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zea mays; Exotic pest; High plains virus; Plant quarantine; Phytosanitary analysis.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000500688

Protective effect and economic impact of insecticide application methods on barley
Provedor de dados: 86
Autores: Stoetzer,Alfred; Kawakami,Jackson; Marsaro Júnior,Alberto Luiz; Lau,Douglas; Pereira,Paulo Roberto Valle da Silva; Antoniazzi,Noemir.
The objective of this work was to evaluate the protective effect of different forms of insecticide application on the transmission of yellow dwarf disease in barley cultivars, as well as to determine the production costs and the net profit of these managements. The experiments were carried out during 2011 and 2012 growing seasons, using the following managements at main plots: T1, seed treatment with insecticide (ST) + insecticide on shoots at 15-day interval; T2, just ST; T3, insecticide applied on shoots, when aphid control level (CL) was reached; T4, without insecticide; and T5, ST + insecticide on shoots when CL was reached. Different barley cultivars - BRS Cauê, BRS Brau and MN 6021 - were arranged in the subplots. Insecticides lambda cyhalothrin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hordeum vulgare; Metopolophium dirhodum; Rhopalosiphum padi; Seed treatment; Yellow dwarf disease.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000300153

Molecular identification based on coat protein sequences of the Barley yellow dwarf virus from Brazil
Provedor de dados: 63
Autores: Mar,Talita Bernardon; Lau,Douglas; Schons,Jurema; Yamazaki-Lau,Elene; Nhani Jr.,Antônio.
Yellow dwarf disease, one of the most important diseases of cereal crops worldwide, is caused by virus species belonging to the Luteoviridae family. Forty-two virus isolates obtained from oat (Avena sativa L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), corn (Zea mays L.), and ryegrass (Lolium multiflorum Lam.) collected between 2007 and 2008 from winter cereal crop regions in southern Brazil were screened by polymerase chain reaction (PCR) with primers designed on ORF 3 (coat protein - CP) for the presence of Barley yellow dwarf virus and Cereal yellow dwarf virus (B/CYDV). PCR products of expected size (~357 bp) for subgroup II and (~831 bp) for subgroup I were obtained for three and 39 samples, respectively. These products were cloned...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Luteoviridae; Poaceae; Small grains; Wheat; Oat.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000600008

Hipersensibilidade e necrose sistêmica em Nicotiana benthamiana transformada com o gene de resistência Sw-5 de tomateiro
Provedor de dados: 102
Autores: Lau,Douglas; Oliveira,Julio Cezar F. de; Lau,Elene Y.; Brommonschenkel,Sérgio H.
O gene Sw-5 do tomateiro confere resistência a várias espécies de tospovírus e codifica uma proteína contendo domínios de ligação a nucleotídeos e repetições ricas em leucina. Tomateiros com Sw-5 exibem reações necróticas nas folhas inoculadas com tospovírus. Estas reações e a estrutura da proteína Sw-5 indicam que a resistência ocorre por meio do reconhecimento do patógeno e desencadeamento da resposta de hipersensibilidade. A capacidade de Sw-5 de conferir resistência a tospovírus em tabaco selvagem (Nicotiana benthamiana Domin.) foi avaliada em plantas transgênicas. Uma construção com a seqüência aberta de leitura de Sw-5 e sua região 3’ não-traduzida sob controle do promotor 35S do CaMV foi utilizada para transformação de N. benthamiana via...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Resistência a vírus; Expressão heteróloga; Transdução de sinais.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582006000300002

Ralstonia solanacearum em viveiros clonais de eucalipto no Brasil
Provedor de dados: 102
Autores: Alfenas,Acelino C.; Mafia,Reginaldo G.; Sartório,Robert C.; Binoti,Daniel H.B.; Silva,Ricardo R.; Lau,Douglas; Vanetti,Cláudia A.
A incidência da murcha bacteriana, causada por Ralstonia solanacearum, em viveiros clonais de eucalipto, no período de abril a setembro de 2005, resultou no descarte de cerca de 553.991 minicepas, 6.837.691 propágulos na fase de enraizamento e 11.266.819 mudas, nos Estados da Bahia, do Espírito Santo, do Maranhão, de Minas Gerais e do Pará, totalizando um prejuízo estimado em, no mínimo, seis milhões de reais (US$ 2,7 milhões). Em minijardim clonal, a doença caracteriza-se por necrose foliar, escurecimento anelar ou completo do lenho, murcha e morte de minicepas. Os sintomas na parte aérea são similares à morte gradual de minicepas submetidas a podas drásticas ou com sistema radicular malformado. Na fase de enraizamento, miniestacas infectadas podem...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Murcha bacteriana; Murcha vascular; Eucalyptus spp.; Propagação clonal; PCR/RFLP; DNA.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582006000400005

Resultados agronômicos e qualitativos da nova cultivar de trigo 'BRS Marcante'
Provedor de dados: 65
Autores: Caierão,Eduardo; Silva,Márcio Só e; Scheeren,Pedro Luiz; Castro,Ricardo Lima de; Eichelberger,Luiz; Nascimento Junior,Alfredo do; Guarienti,Eliana Maria; Miranda,Martha Zavariz de; Pires,João Leonardo Fernandes; Maciel,João Leodato Nunes; Chaves,Márcia Soares; Santana,Flávio Martins; Costamilan,Leila; Lima,Maria Imaculada Pontes Moreira; Lau,Douglas; Pereira,Paulo Roberto Valle da Silva; Silva Júnior,José Pereira da; Wiethölter,Sirio; Cunha,Gilberto Rocca da.
A cultivar de trigo 'BRS Marcante' foi desenvolvida pela Embrapa, envolvendo um híbrido F1 do cruzamento entre as linhagens PF 980533 e PF 970227 com a cultivar 'BRS Guamirim', realizado em telado, na Embrapa Trigo, no inverno de 2003. As gerações segregantes foram conduzidas pelo método genealógico e a linhagem resultante, nomeada de PF 080310. A cultivar caracteriza-se pela sua ampla capacidade de adaptação às condições de cultivo do sul do Brasil, pelo bom potencial de rendimento de grãos e qualidade industrial da classe Pão
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Melhoramento; Germoplasma; Cereais; Triticum aestivum.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000400644