Identificação e caracterização patogênica da microflora associada a acácia mangium WILLD. no município de Itacoatiara - AM

Abstract

The identification and characterization of a causal agent associated with plant diseases is the first step towards integrated disease management. It is common in the areas of planting the occurrence of diseases in the form of leaf spots or lesions that have not been well studied and that certainly contribute to the reduction of the productive capacity of this species. Acacia mangium Willd. It is an Australian arboreal exotic forest species belonging to the Fabaceae family, which stands out for its high energy potential, easy adaptation and rusticity. The species has been successfully used as an energy source in the ceramic industry in the Amazon. A. mangium is also reported as a multipurpose species and is used to recover degraded areas. The present work aimed to identify fungi associated with Acacia mangium Willd. leaves in the municipality of Itacoatiara-AM. In 2017, a fungal survey was carried out by collecting and sampling leaves with symptoms of spots and lesions in forest plantations owned by Litiara Industria Cerâmica da Amazônia Ltda., Located at Km 19 of Rodovia AM-010, Itacoatiara -AM. After collection and sampling, the characterization was made in a proper form, containing, besides the description of symptoms, the date, place of collection and name of the collector. Identification of the pathogens associated with the lesions was performed in the laboratory by the direct and indirect method, obtaining a total of 60 isolates. After isolation, the Daily Mycelial Growth Rate (MDCT) was obtained. From the obtained isolates the fungi Cylindrocladium sp. and Colletotrichum sp. After isolation and identification, 7-day growth colonies were subcultured to new plates containing BDA (Potato-Dextrose-Agar) for determination of Daily Mycelial Growth Rate (MDCT). The statistical design used for the Daily Mycelial Growth Rate was the completely randomized (ICT). Data were subjected to analysis of variance and means were compared. This is one of the first reports of leaf spot caused by Cylindrocladium sp. In A. mangium in Amazonas and Brazil.