Riqueza de fungos micorrízicos arbusculares em remanescente de Mata Atlântica de tabuleiro costeiro do Rio Grande do Norte

Abstract

The Coastal tablelands constitute a geoenvironmental unit distributed throughout the Brazilian coast, whose main vegetation is the Atlantic Forest. Arbuscular Mycorrhizal Fungi (AMF) are obligatory symbionts of plants, which represent an important component of the soil microbiota in natural and agricultural ecosystems. Study of diversity in coastal environments are relevant, presenting biotic and abiotic peculiarities. In addition, inventories of AMF in coastal systems conducted in Brazil are limited. Protected areas are needed to ensure the conservation of habitats where the AMF occur naturally and have evolved, representing an appropriate place for in situ conservation. The objective of this study was to evaluate the diversity of a coastal tablelands complex of the Atlantic Forest domain of Rio Grande do Norte, in order to increase knowledge about the composition and distribution of this group of organisms. For this, nine soil samples were studied for taxonomic identification, three samples of the rainy period and six of dry. We found 47 species of AMF (30 in the rainy season and 26 in the dry season), distributed in nine families: Acaulosporaceae (9 spp), Ambisporaceae (3 spp.), Dentiscutataceae (4 spp.), Diversisporaceae (4 spp.), Entrophosporaceae (4 spp.), Gigasporaceae (3 spp.), Glomeraceae (14 spp.), Racocetraceae (2 sp.), Scutellosporaceae (3 spp.) and 17 genera. Of the 138 species, recorded in the Atlantic Forest biome, 35% correspond to the AMF in coastal tablelands of Atlantic Forest remnants studied. This represents 16% of species known for Phyllum. For Brazil it represents 30% of the species. For the Northeast, it represents 38%. For the RN there were only 41 registered species, however this number was increased to 55 with the data obtained in this present study. In addition, the area presents 37% of the species reported in globally protected areas. However, species composition changed between the periods, with the highest number of species in the rainy season. In addition, species richness was more representative in the rainy period than in the dry season, even though the sample strength was lower in the rainy season. The genera Acaulospora and Glomus were the most representative, in addition, the registration of Glomus spinuliferum Sieverd & Oehl, was increased for Brazil and for the Atlantic Forest biome. The results obtained demonstrate the diversity potential of AMF present in coastal tablelands areas in remnants of Atlantic Forest.