Guarana plant is a native of the Amazon region. Due to its high amount of caffeine and tannins, the seed has medicinal and stimulating properties. The guarana industry has grown exponentially in recent years; however, little information is available about associated mycobiota, particularly endophytic fungi. The present study aimed to compare the distribution and diversity of endophytic fungi associated with the leaves and seeds of anthracnose-resistant and susceptible guarana plants produced in Maués and Manaus, Amazonas State, Brazil. A total of 7514 endophytic fungi were isolated on Potato Dextrose Agar, Sabouraud and Czapek media, and grouped into 77 morphological groups. Overall, fungal communities in guarana leaves and seeds were mainly composed by Colletotrichum and Fusarium genera, but also by Chondrostereum, Clonostachys, Curvularia, Hypomontagnella, Lentinus, Neopestalotiopsis, Nigrospora, Peroneutypa, Phyllosticta, Simplicillium and Tinctoporellus. Obtained results indicate that some members of Colletotrichum and Fusarium genera may have experienced dysbiosis during the guarana domestication process, suggesting that some individuals may behave as latent pathogens. The susceptible guarana genotype cultivated in Manaus presented higher fungal diversity. The relative abundance of taxa and diversity among samples suggests that communities are structured by genotype and geographic location. This is the first report of mycobiota in both guarana leaves and seeds.This research was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES) project Pró-Amazônia n◦3287/13. C.S. (Carla Santos) and N.L. were supported by FCT under the scopeof the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004)funded by the European Regional Development Fund under the scope of Norte2020 - Programa OperacionalRegional do Norte. C.S. (Cledir Santos) was supported by the Universidad de La Frontera (Temuco, Chile) withpartial funding from the Project PIA19-0001.info:eu-repo/semantics/publishedVersio
