RESUMEN

Different groups of fungi have been reported to interact with ants. Recent studies have shown that fungi of the order Chaetothyriales are important components of ant-fungus networks, including members of the family Trichomeriaceae, which is particularly rich in fungi isolated from carton ants nests. One of the still understudied ant-related environments are ants' infrabuccal pockets and pellets, which often contain fungal matter. The aim of this work was to determine the systematic and phylogenetic position of two slow growing strains of Trichomeriaceae isolated from infrabuccal pellets of Formica polyctena ants. Molecular analyses based on maximum likelihood and bayesian inference, using sequences of two ribosomal DNA markers: ITS and LSU have shown that the isolated strains form a monophyletic clade within the family Trichomeriaceae, sister to a clade formed by representatives of the genus Trichomerium. Morphological analyses additionally justified distinctiveness of the isolated strains, which have different morphology of conidia and conidiophores than Trichomerium representatives. Therefore, our results show that the isolated strains represent a new species within a not yet described fungal genus. Due to the strains' isolation source and their close relatedness to a fungal strain isolated from a carton nest of Lasius fuliginosus, we propose a name Formicomyces microglobosus Siedlecki & Piatek for this fungus. While our discovery strengthens a hypothesis of the multiple, independent evolution of ant-associated fungi in the family Trichomeriaceae, the ecology of F. microglobosus still remains to be characterized.

Asunto(s)

Hormigas , Ascomicetos , Animales , Filogenia , Hormigas/microbiología , Teorema de Bayes , Ascomicetos/genética , Hongos , Esporas Fúngicas , Simbiosis

RESUMEN

Studies on carton nesting ants and domatia-dwelling ants have shown that ant-fungi interactions may be much more common and widespread than previously thought. Until now, studies focused predominantly on parasitic and mutualistic fungi-ant interactions occurring mostly in the tropics, neglecting less-obvious interactions involving the fungi common in ants' surroundings in temperate climates. In our study, we characterized the mycobiota of the surroundings of Formica polyctena ants by identifying nearly 600 fungal colonies that were isolated externally from the bodies of F. polyctena workers. The ants were collected from mounds found in northern and central Poland. Isolated fungi were assigned to 20 genera via molecular identification (ITS rDNA barcoding). Among these, Penicillium strains were the most frequent, belonging to eight different taxonomic sections. Other common and widespread members of Eurotiales, such as Aspergillus spp., were isolated very rarely. In our study, we managed to characterize the genera of fungi commonly present on F. polyctena workers. Our results suggest that Penicillium, Trichoderma, Mucor, Schwanniomyces and Entomortierella are commonly present in F. polyctena surroundings. Additionally, the high diversity and high frequency of Penicillium colonies isolated from ants in this study suggest that representatives of this genus may be adapted to survive in ant nests environment better than the other fungal groups, or that they are preferentially sustained by the insects in nests.