Diversidade e taxonomia polifásica de leveduras associadas à família Bromeliaceae na Mata Atlântica Setentrional

Abstract

The tropical rain forests are ecosystems with a high biodiversity richness that occupy about 7% of the terrestrial surface. The Atlantic Forest biome is a representing of these pluvial forests, containing high rates of endemism and considered a conservation priority. Bromeliads are predominantly Neotropical plants, recognized as regional hotspots of diversity due to its capability to form associations with different taxa and therefore used as model systems for ecology. Knowledge about the diversity of yeasts associated with phylloplane (leaf surface) and bromeliad water tank (phytotelma) has been relevant in the last 20 years, but there are still several gaps left over the structuring factors of these communities and how these are maintained across different regions. The objective of this work was to describe the taxonomic yeast diversity, focusing on the description of new species associated with the phylloplane (leaves) and antosphere (floral structures) of bromeliads collected at four sites of the Northern Atlantic Forest of Alagoas - Brazil, as well as to determine their possible patterns of geographic distribution. In total, we identified 303 yeast and reported a richness of 114 species, about 50% of them classified as possible new species, and there was a prevalence (86%) of phylum Basidiomycota on phylloplane. Alpha diversity analysis of yeast community at Maceio site showed the highest values of species richness S = 42 and Shannon-Weaver index H '= 3.524, as well as a lower dominance (0.03893) compared to the other sites sampled. The four sampling sites showed a high heterogeneity was not explained by any of environmental factors measured nor by geographic factors such as the distance between the points and their distance to the equator. However, we observed in all sites a significant relationship between the richness and composition of yeast and bromeliad species, suggesting a relationship between the yeasts and their hosts. Bromeliads were ratified as na ecological model and a preponderant substrate for studies with yeasts, in particular for the isolation and description of new taxa.