Culture-dependent methods reveal the diversity of endophytic fungi of Psidium cattleianum leaves (Myrtales: Myrtaceae)

Endophytic fungi are a diverse group of microorganisms that reside within plant tissues and play a crucial ecological role in the development of their hosts. Psidium cattleianum (Myrtales: Myrtaceae: ‘Cattley guava’) is a Brazilian native species with economic potential due to the diverse applications of its fruits, wood, and essential oils. Despite their significance, the diversity of endophytic fungi associated with P. cattleianum remains unexplored. Here, we investigated the diversity of endophytic fungi in the leaves of this plant using cultivation-dependent isolation methods, analysis of the macroscopic characters of the isolates, and phylogenetic analyses employing the ITS barcode marker. A total of 396 isolates, classified into 25 fungal taxa, were obtained, namely, Alternaria, Aspergillus, Cladosporium, Colletotrichum, Coprinellus, Coriolopsis, Diaporthe, Induratia, Mycosphaerella, Muyocoprom, Myrmecridium, Neofusicoccum, Pantospora, Paracamarosporium, Parapallidocercospora, Paraphaeosphaeria, Penicillium, Perenniporia, Phaeophleospora, Phyllosticta, Pseudofusicoccum, Talaromyces, Xylaria, Sordariomycetes, and Xylariomycetes. Our findings reveal a significant diversity of fungi associated with P. cattleianum leaves; however, our study suggests an even greater diversity of fungi associated with this plant species. Interestingly, although P. cattleianum shares endophytic fungi with other plants in the Myrtaceae family, this plant species harbors a unique fungal community. This distinction is evidenced by certain fungal genera and seven potentially new phylogenetic species, isolated in this study.