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Registro Completo |
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Biblioteca(s): |
Embrapa Mandioca e Fruticultura. |
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Data corrente: |
16/04/2004 |
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Data da última atualização: |
16/04/2004 |
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Autoria: |
FAUQUET, C. M.; FONDONG, V.; PITA, J.; TORES-JEREZ, I.; OTIM-NAPE, W. G.; OGWAL, S.; SANGARE, A.; REY, C.; BROWN, J. K.; BEACHY, R. N. |
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Título: |
Etiology of the cassava mosaic disease in Africa reveals increasing complexity and diversity. |
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Ano de publicação: |
1998 |
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Fonte/Imprenta: |
Revista Brasileira de Mandioca, Salvador, v. 17, p. 39, nov., 1998., Suplemento. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Since the beginning of this century cassava mosaic disease has been reported in all the African countries growing cassava. Symptoms vary somewhat from one country to the nex but always show mosaic, leaf curl and a significant reduction in yield. The presence of a dramatic new virus epidemic in cassava has caused increasing concern in Uganda since 1986. The new disease induces very severe symptoms, often resulting in total yield loss and failure of cutting establishment from infected stems. Two virus species have been isolated both from these plants and the whitefly vectors; the African cassava mosaic virus (ACMV) and the East African cassava mosaic virus (EACMV). Infection with the former is correlated with mild symptoms whilst presence of the latter causes severe symptoms in the crop. Sequence comparison of the EACMV virus isolate with other cassava viruses revealed that it is a recombinant between EACMV and ACMV. A large sampling of infected cassava plants from Uganda, allowed us to identify mild and severe strains of both irrespective of the symptoms induced on cassava, thereby indicating the absence of correlation between recombination and symptom severety. Comparison of mitochondria DNA sequences from whiteflies collected in each ecological situation indicated that a distinct population of B. tabaci, presently of unknown origin, is correlated with the presence of the severe symptoms and therefore with EACMV/UG. In west Africa the variety of symptoms seen on cassava are difficult to the cassava genotype or to the virus isolate. The two virus species; ACMV and EACMV, have also been isolated in Camerron and in Ivory Coast. A range of symptoms have been recorded in cassava and can now be reproduced on artificial hosts from crude sap and from infectious clones. Studies have revealed that, while ACMV is very similar throughout Africa, EACMV reveals the presence of different recombined fragments of unknown origin. The importance and relevance of these findings relative to symptoms on cassava and the epidemic in Uganda will be discussed. MenosAbstract: Since the beginning of this century cassava mosaic disease has been reported in all the African countries growing cassava. Symptoms vary somewhat from one country to the nex but always show mosaic, leaf curl and a significant reduction in yield. The presence of a dramatic new virus epidemic in cassava has caused increasing concern in Uganda since 1986. The new disease induces very severe symptoms, often resulting in total yield loss and failure of cutting establishment from infected stems. Two virus species have been isolated both from these plants and the whitefly vectors; the African cassava mosaic virus (ACMV) and the East African cassava mosaic virus (EACMV). Infection with the former is correlated with mild symptoms whilst presence of the latter causes severe symptoms in the crop. Sequence comparison of the EACMV virus isolate with other cassava viruses revealed that it is a recombinant between EACMV and ACMV. A large sampling of infected cassava plants from Uganda, allowed us to identify mild and severe strains of both irrespective of the symptoms induced on cassava, thereby indicating the absence of correlation between recombination and symptom severety. Comparison of mitochondria DNA sequences from whiteflies collected in each ecological situation indicated that a distinct population of B. tabaci, presently of unknown origin, is correlated with the presence of the severe symptoms and therefore with EACMV/UG. In west Africa the variety of symptoms seen on c... Mostrar Tudo |
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Categoria do assunto: |
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Marc: |
LEADER 02734naa a2200229 a 4500
001 1651728
005 2004-04-16
008 1998 bl uuuu u00u1 u #d
100 1 $aFAUQUET, C. M.
245 $aEtiology of the cassava mosaic disease in Africa reveals increasing complexity and diversity.
260 $c1998
520 $aAbstract: Since the beginning of this century cassava mosaic disease has been reported in all the African countries growing cassava. Symptoms vary somewhat from one country to the nex but always show mosaic, leaf curl and a significant reduction in yield. The presence of a dramatic new virus epidemic in cassava has caused increasing concern in Uganda since 1986. The new disease induces very severe symptoms, often resulting in total yield loss and failure of cutting establishment from infected stems. Two virus species have been isolated both from these plants and the whitefly vectors; the African cassava mosaic virus (ACMV) and the East African cassava mosaic virus (EACMV). Infection with the former is correlated with mild symptoms whilst presence of the latter causes severe symptoms in the crop. Sequence comparison of the EACMV virus isolate with other cassava viruses revealed that it is a recombinant between EACMV and ACMV. A large sampling of infected cassava plants from Uganda, allowed us to identify mild and severe strains of both irrespective of the symptoms induced on cassava, thereby indicating the absence of correlation between recombination and symptom severety. Comparison of mitochondria DNA sequences from whiteflies collected in each ecological situation indicated that a distinct population of B. tabaci, presently of unknown origin, is correlated with the presence of the severe symptoms and therefore with EACMV/UG. In west Africa the variety of symptoms seen on cassava are difficult to the cassava genotype or to the virus isolate. The two virus species; ACMV and EACMV, have also been isolated in Camerron and in Ivory Coast. A range of symptoms have been recorded in cassava and can now be reproduced on artificial hosts from crude sap and from infectious clones. Studies have revealed that, while ACMV is very similar throughout Africa, EACMV reveals the presence of different recombined fragments of unknown origin. The importance and relevance of these findings relative to symptoms on cassava and the epidemic in Uganda will be discussed.
700 1 $aFONDONG, V.
700 1 $aPITA, J.
700 1 $aTORES-JEREZ, I.
700 1 $aOTIM-NAPE, W. G.
700 1 $aOGWAL, S.
700 1 $aSANGARE, A.
700 1 $aREY, C.
700 1 $aBROWN, J. K.
700 1 $aBEACHY, R. N.
773 $tRevista Brasileira de Mandioca, Salvador$gv. 17, p. 39, nov., 1998., Suplemento.
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Registro original: |
Embrapa Mandioca e Fruticultura (CNPMF) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Cerrados. Para informações adicionais entre em contato com cpac.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
29/06/1992 |
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Data da última atualização: |
29/06/1992 |
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Autoria: |
GALRAO, E. Z.; SOUZA, D. M. G. de; PERES, J. R. R. |
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Título: |
Caracterizacao de deficiencias nutricionais em solos de varzeas da regiao dos cerrados. |
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Ano de publicação: |
1984 |
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Fonte/Imprenta: |
Pesquisa Agropecuaria Brasileira, v.19, n.9, p.1091-1101, 1984. |
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Idioma: |
Português |
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Conteúdo: |
Avaliou-se, em casa de vegetacao, o efeito do calcario, S, Cu, Zn, B e Mo na producao da materia seca, numero e peso de nodulos da soja (Glycine max (L.) Merril), var. Doko, em dez solos de varzeas da Regiao dos Cerrados com ampla variacao. Utilizou-se como esquema experimental um fatorial fracionado 2 elevado a 6, em dois blocos. Os nutrientes foram aplicados na base de mg do elemento por litro de solo seco (mg/1): 0 e 30 de S (enxofre elementar), 0 e 2 Cu (CuCl), 0 e 3 de Zn (ZnO), 0 e 0,5 de B (H3BO3), 0 e 0,25 de Mo (Na2 MoO4 2H2O) e, 0 e uma dose de calcario, determinada pelo metodo SMP, para elevar o pH de cada solo a 5,5. A adubacao basica (mg/1) constou de 100 de P e 127 de k (KH2PO4), e mais 73 de K (KCl). Dos dez solos estudados, oito responderam a calagem. Quanto ao efeito de cada nutriente nos paramentros avaliados (materia seca, numero e peso de nodulos), as respostas obedeceram a seguinte ordem: B>S>Cu>Zn. Nao foi constatada resposta ao molibdenio. Houve efeito das interacoes calcario x B, calcario x S, calcario x Zn, Cu x Zn e S x B, nos paramentros avaliados. |
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Palavras-Chave: |
Casa de vegetacao; Cultivar Doko. |
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Thesagro: |
Adubação; Boro; Calcário; Cerrado; Cobre; Enxofre; Glycine Max; Matéria Seca; Molibdênio; Produção; Soja; Solo; Várzea; Zinco. |
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Categoria do assunto: |
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Marc: |
LEADER 01947naa a2200337 a 4500
001 1547406
005 1992-06-29
008 1984 bl uuuu u00u1 u #d
100 1 $aGALRAO, E. Z.
245 $aCaracterizacao de deficiencias nutricionais em solos de varzeas da regiao dos cerrados.
260 $c1984
520 $aAvaliou-se, em casa de vegetacao, o efeito do calcario, S, Cu, Zn, B e Mo na producao da materia seca, numero e peso de nodulos da soja (Glycine max (L.) Merril), var. Doko, em dez solos de varzeas da Regiao dos Cerrados com ampla variacao. Utilizou-se como esquema experimental um fatorial fracionado 2 elevado a 6, em dois blocos. Os nutrientes foram aplicados na base de mg do elemento por litro de solo seco (mg/1): 0 e 30 de S (enxofre elementar), 0 e 2 Cu (CuCl), 0 e 3 de Zn (ZnO), 0 e 0,5 de B (H3BO3), 0 e 0,25 de Mo (Na2 MoO4 2H2O) e, 0 e uma dose de calcario, determinada pelo metodo SMP, para elevar o pH de cada solo a 5,5. A adubacao basica (mg/1) constou de 100 de P e 127 de k (KH2PO4), e mais 73 de K (KCl). Dos dez solos estudados, oito responderam a calagem. Quanto ao efeito de cada nutriente nos paramentros avaliados (materia seca, numero e peso de nodulos), as respostas obedeceram a seguinte ordem: B>S>Cu>Zn. Nao foi constatada resposta ao molibdenio. Houve efeito das interacoes calcario x B, calcario x S, calcario x Zn, Cu x Zn e S x B, nos paramentros avaliados.
650 $aAdubação
650 $aBoro
650 $aCalcário
650 $aCerrado
650 $aCobre
650 $aEnxofre
650 $aGlycine Max
650 $aMatéria Seca
650 $aMolibdênio
650 $aProdução
650 $aSoja
650 $aSolo
650 $aVárzea
650 $aZinco
653 $aCasa de vegetacao
653 $aCultivar Doko
700 1 $aSOUZA, D. M. G. de
700 1 $aPERES, J. R. R.
773 $tPesquisa Agropecuaria Brasileira$gv.19, n.9, p.1091-1101, 1984.
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Embrapa Cerrados (CPAC) |
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