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1.
Biosci. j. (Online) ; 32(2): 431-435, mar./abr. 2016. tab
Article Dans Anglais | LILACS | ID: biblio-965299

Résumé

Panama disease, or fusarium wilt disease, caused by the fungus Fusarium oxysporum f.sp. cubense is a disease causing great losses in banana production worldwide, hindering production in certain areas of the world. In Brazil, banana crop has suffered great losses due to favorable soil and climate conditions for the development of pests and diseases and, also, by the low technological level used in most growing areas of the country. Therefore, the use of genetic resistance for the control of this disease becomes a promising alternative, making possible the cultivation of bananas in some areas that had been decimated by this pathogen. Thus, this study evaluated the performance of banana genotypes subjected to artificial inoculation with F. oxysporum f.sp. cubense in a nursery and in the field. The genotypes Tropical, Pacovan, Caipira, Japira, Princesa and Fhia-18, besides 'Prata Anã', as a susceptible control, were evaluated in a completely randomized design, with 4 replications, and each replication consisted of two plants. The seedling were also subjected to a field test in a completely randomized design, with three replications. Disease severity, for external symptoms, was evaluated 50 days after inoculation, using a rating scale in which, all plants, except for Fhia-18, which did not show symptoms, had initial yellowing of older leaves. Field evaluations consisted of measuring plant height and diameter, and after harvesting the banana bunches, internal symptoms were observed in the pseudostems. Cultivars Prata- Anã and Caipira had greater susceptibility to the disease.


Alguns problemas da bananicultura mundial se tornaram também problemas para o Brasil. A doença fúngica de solo, que limita o cultivo da banana 'Maçã' é de difícil controle e tornou-se grave problema em algumas importantes áreas de cultivo é o mal-do-Panamá, uma das mais importantes doenças da bananeira, causada pelo fungo Fusarium oxysporum f.sp. cubense, provoca elevadas perdas na produção e pode persistir no solo por muitos anos. Portanto o objetivo desse trabalho é avaliar o comportamento de genótipos de bananeira quando submetidos à inoculação artificial de Fusarium oxysporum f.sp. cubense em situação de viveiro de mudas e situação de campo. Foram avaliados os genótipos Tropical, Pacovan, Caipira, Japira, Princesa e Fhia-18, além da 'Prata Anã' como testemunha (suscetível), em delineamento inteiramente casualizado, com 4 repetições, sendo duas plantas por repetição. As mudas também foram submetidas a teste de campo em que o delineamento experimental foi inteiramente casualizado com 3 repetições. A severidade da doença quanto aos sintomas externos foi avaliada aos 50 dias após a inoculação utilizando escala de notas, na qual todas as plantas, com exceção da Fhia-18 que não apresentou sintomas, apresentaram amarelecimento inicial nas folhas velhas.No teste de campo foram avaliados, altura e diâmetro das plantas e após a retirada dos cachos, foi observado os sintomas internos do pseudocaule onde as cultivares Prata-Anã e Caipira apresentaram maior suscetibilidade a doença.


Sujets)
Production végétale , Musa , Fusarium , Génotype
2.
Indian J Exp Biol ; 2013 Jul; 51(7): 531-542
Article Dans Anglais | IMSEAR | ID: sea-147624

Résumé

An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 ± 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 ± 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5–15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, β-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.


Sujets)
Marqueurs biologiques/analyse , Cellules cultivées , Fusarium/génétique , Fusarium/pathogénicité , Interactions hôte-pathogène , Kinétine/pharmacologie , Musa/effets des médicaments et des substances chimiques , Musa/génétique , Musa/microbiologie , Phénylurées/pharmacologie , Maladies des plantes/génétique , Maladies des plantes/immunologie , Maladies des plantes/microbiologie , Pousses de plante/effets des médicaments et des substances chimiques , Pousses de plante/génétique , Pousses de plante/microbiologie , Thiadiazoles/pharmacologie
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