Seleção de fungos degradadores de madeira para uso na destoca biológica de Eucalyptus spp
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Data
2011-07-06
Autores
Negrão, Djanira Rodrigues [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O eucalipto é a arbórea mais plantada no Brasil, devido ao seu amplo uso e após seu corte, os tocos e raízes que permanecem no local, dificultam o manejo da cultura. Com base nessa necessidade, o objetivo do presente estudo foi avaliar as características fisiológicas e funcionais de fungos basidiomicotas, isolados de campos de reflorestamento de Eucalyptus spp., com vistas à possibilidade do uso destes na destoca natural. Os fungos Pycnoporus sanguineus, Lentinus bertieri, Xylaria sp. e Lentinula edodes e um isolado não identificado foram estudados. No primeiro experimento, avaliou-se a patogenicidade dos mesmos em plantas de eucalipto urograndis (10 meses de idade), através da inoculação de disco de meio de cultura colonizado e não colonizado (Testemunha). As avaliações foram feitas aos 30 e 60 dias após a inoculação, com base no tamanho das lesões internas e externas. No segundo experimento, avaliou-se o crescimento micelial dos fungos P. sanguineus, L. bertieri, Xylaria sp., L. edodes e S. ostrea, em substrato à base de serragem enriquecida com farelos, e em três composições de meios de cultura, Batata-Dextrose-Ágar (BDA); Malte-Ágar (MA) e Serragem-Dextrose-Ágar (SDA), e incubados a 23, 27 e 31ºC. No terceiro experimento, avaliou-se a produção das enzimas ligninocelulolíticas lacase e celulase, e outras ligadas à degradação de tecidos vegetais, as proteases, pectinases e lipase, em meios de cultura específicos. No quarto experimento, estudou-se, pelo método “soil block”, a perda de massa (%) de corpos-de-prova de eucalipto urograndis, inoculados com os fungos P. sanguineus, L. bertieri, Xylaria sp. e L. edodes, mantidos sob dois regimes de umidade (50 e 100%), e avaliados aos 30, 60, 90 e 120 após inoculação. Estudaram-se também as características químicas da madeira, após 120 dias da inoculação
The Eucalyptus spp. tree is the most planted in Brazil, due to its widespread use and after its use, the stumps and roots that remains in the area, hinder crop management. Based on this need, the purpose of this work was evaluate the physiological and functional characteristics of basidiomycetes fungi, obtained in reforestation fields of Eucalyptus spp., with the possibility of using the fungi in natural stump removal. Pycnoporus sanguineus, Lentinus bertieri, Xylaria sp., Stereum ostrea and a unidentified isolate, were studied. In the first, was evaluate the fungi pathogenicity in eucalipt urograndis plants (10 months old), by means of disk inoculation into culture medium colonized and non-colonized (control) by fungi. Evaluations were performed at 30 and 60 days after inoculation based on the external and internal size of lesions. In experiment 2, the mycelial growth of P. sanguineus, L. bertieri, Xylaria sp., L. edodes and S. ostrea was evaluated in bran and sawdust-based substrate, as well as in three culture media: Potato-Dextrose-Agar (PDA), Malt-Agar (MA) and Sawdust-Dextrose-Agar (SDA), and at three incubation temperatures, at 23, 27 and 31ºC. In experiment 3, the production of lignolytic enzymes lacase and cellulase, and other enzymes related to degradation of plant tissues, like protease, pectinases and lipase was assessed in specific culture media. In experiment 4, mass loss (%) and chemical features of eucalipt urograndis wood degraded by the soil block method were evaluated by the P. sanguineus, L. bertieri, Xylaria sp. and L. edodes fungi. Thus, test specimens were inoculated with the fungi and kept under two moisture regimes, 50 and 100%, and incubated at 25 ±2ºC. Mass loss was assessed at 30, 60, 90 and 120 days after inoculation. The chemical features of eucalipt urograndis test specimens were only analyzed at 120 days
The Eucalyptus spp. tree is the most planted in Brazil, due to its widespread use and after its use, the stumps and roots that remains in the area, hinder crop management. Based on this need, the purpose of this work was evaluate the physiological and functional characteristics of basidiomycetes fungi, obtained in reforestation fields of Eucalyptus spp., with the possibility of using the fungi in natural stump removal. Pycnoporus sanguineus, Lentinus bertieri, Xylaria sp., Stereum ostrea and a unidentified isolate, were studied. In the first, was evaluate the fungi pathogenicity in eucalipt urograndis plants (10 months old), by means of disk inoculation into culture medium colonized and non-colonized (control) by fungi. Evaluations were performed at 30 and 60 days after inoculation based on the external and internal size of lesions. In experiment 2, the mycelial growth of P. sanguineus, L. bertieri, Xylaria sp., L. edodes and S. ostrea was evaluated in bran and sawdust-based substrate, as well as in three culture media: Potato-Dextrose-Agar (PDA), Malt-Agar (MA) and Sawdust-Dextrose-Agar (SDA), and at three incubation temperatures, at 23, 27 and 31ºC. In experiment 3, the production of lignolytic enzymes lacase and cellulase, and other enzymes related to degradation of plant tissues, like protease, pectinases and lipase was assessed in specific culture media. In experiment 4, mass loss (%) and chemical features of eucalipt urograndis wood degraded by the soil block method were evaluated by the P. sanguineus, L. bertieri, Xylaria sp. and L. edodes fungi. Thus, test specimens were inoculated with the fungi and kept under two moisture regimes, 50 and 100%, and incubated at 25 ±2ºC. Mass loss was assessed at 30, 60, 90 and 120 days after inoculation. The chemical features of eucalipt urograndis test specimens were only analyzed at 120 days
Descrição
Palavras-chave
Eucalipto, Fungos na agricultura, Fungos de degradação branca, Degradação biológica, Degradação da madeira, Natural stump removal, White rot fungus, Wood decay
Como citar
NEGRÃO, Djanira Rodrigues. Seleção de fungos degradadores de madeira para uso na destoca biológica de Eucalyptus spp. 2011. xiii, 95 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas de Botucatu, 2011.