Avaliação física e microscópica da madeira de Eucalyptus sp. frente ao ataque de fungos prospectados do cerrado

Abstract

Wood, widely used in various sectors, is susceptible to the action of biodegrading agents, such as xylophagous fungi, especially in environments with high humidity, can suffer degradation that compromises its physical and structural properties. The objective of this study was to evaluate the resistance of Eucalyptus sp. wood to the attack of fungi isolated from Cerrado areas, by means of an accelerated rot assay in the laboratory. A total of 19 fungal samples were collected from decomposing wood in the Matinha Park (Monte Carmelo-MG), from which four pure cultures were selected. The methodology followed the AWPA E10-16 standard, using flasks with moistened soil and wooden specimens exposed to fungi for three months. After this period, the basic and apparent density, the diameter of the vessels and the structure of the wood were analyzed by optical and scanning electron microscopy (SEM). The results indicated that Treatment 1 had the highest density loss, while Treatment 2 had the lowest degradation, possibly due to the presence of the fungus Trichoderma sp., known for its antagonistic action. Microscopic analysis revealed a reduction in vessel diameter in the inoculated treatments, and SEM confirmed fungal colonization with different levels of cell wall deterioration. It is concluded that the fungi prospected from the Cerrado directly affect the integrity of Eucalyptus sp. wood, evidencing the importance of rot assay studies.