Fungos conidiais associados à pupunheira (bactris gasipaes kunth) em áreas de plantio na Amazônia oriental, Brasil.

Abstract

Conidial fungi are important components of the trophic chain acting as parasites of plants and animals, endophytic in plant tissues and decomposers, being one of the first colonizers of litter. Thus, the aim of this study was to investigate the decomposing conidial fungi associated with individuals of Bactris gasipaes Kunth (peach palm) in plantations established in the state of Pará, in addition to evaluating the richness and species composition in these areas. Four collections quarterly were carried out between September/2018 and September/2019, and 15 individuals of B. gasipaes were selected per area. Living substrates (leaflets, rachises) and decaying (sheaths, leaflets, petioles and rachises) were collected, totaling 180 samples. The samples were submitted to the washing technique under running tap water and kept in a moist chamber for up to 45 days. In parallel, living leaflets and rachises were also collected from the same 15 individuals to assess the presence of pathogens and other fungi. These samples were kept in a moist chamber for up to five days. The reproductive structures of the fungi were visualized under a stereomicroscope and mounted on semi-permanent slides for morphological analysis and identification. In total, 103 species of decomposers conidial fungi were identified, distributed in 78 genera and 31 families. Most fungi occurred on lignified substrates, especially the sheaths, with sporadic frequency. Species richness varied significantly between the analyzed substrates, while the composition differed between areas, substrates and collection periods. The data show a high richness of conidial fungi acting as decomposers of B. gasipaes leaves in plantation areas. On living substrates were related only five species of conidial fungi. This study expanded the knowledge of fungi present in the Amazon region, with 12 new records for the state of Pará, including five for the Brazilian Amazon, one for Brazil (Didymostilbe capsici), one for South America (Ellisembia antillana) and two for the American continent (Aculeata aquatica and Ellisembia tarennae.