Funga associada à Elaeis guineensis Jacq. (dendezeiro) na Amazônia Oriental, Brasil

Abstract

Asexual ascomycetes are important components of the trophic and can act as parasites of plants and animals, endophytic in plant tissues and mainly as decomposers, participating in nutrient cycling and ecosystem maintenance. The objective of this work was to carry out a taxonomic study of asexual ascomycetes associated to decomposing parts of leaf litter of Elaeis guineensis Jacq. in plantation areas in the eastern Amazon, Pará, Brazil. Three collections were carried out between the months of December/2022 and August/2023 in the state of Pará (Abaetetuba, Moju and Santa Bárbara do Pará), and which area 15 individuals of E. guineensis were selected, and the sample consisted of living substrates (15 leaflets) and decaying (sheaths, bunches, leaflets, petioles, rachis) were collected, totaling 225 samples. The samples were submitted to the washing technique in running water and, later, conditioned in a humid chamber for up to 45 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, 143 taxa of asexual ascomycetes were identified, distributed in 96 genera, 48 families, 24 orders, and five class. Most fungi occurred in leaflets (59), followed by petioles (48), sheaths (45), rachis (38) and bunches (13). The data indicate a high diversity of asexual ascomycetes acting as decomposers of E. guineensis in plantation areas. On living substrates were related only six species of fungi. This study expanded the knowledge of fungi present in the Amazon region, with new records presented for the Brazilian Amazon (Gyrothrix dichotoma, Harzia patula, Parawiesneriomyces syzygii), for Brazil (Helminthosporium longisinuatum), for South America (Dictyocheirospora gigantica) and nine for the American Continent (Cacumisporium rugosum, Dictyocheirospora suae, Diplococcium capitatum, Distoseptispora appendiculata, Endocalyx indumentum, Pseudoberkleasmium chiangmaiense, Savoryella nypae, Sporidesmium antidesmatis, Trichocladium palmae), in addition to the description of two new species (Diplococcium sp. nov e Sporidesmium sp. nov). Thus, these data contributed to expanding knowledge of fungi associated with oil palm in the Amazon biome, highlighting the importance of carrying out studies in environments that are little explored.