A complete view on the aquatic-derived fungal phylogeny and ecology: The impact of 18S rRNA sequence information and contextual data from public databases and a fungal culture collection

Aquatic-derived fungi colonize a wide range of substrata and can be found in many geographic locations. They have diverse ecological roles, including important ecological and biogeochemcial functions. The number of fungal sequences in public databases is still rising, also fungal culture collections provide enormous genetic resources. To examine the impact of these resources on the phylogeny of the aquatic-derived fungi, based on the 18S rRNA SSU gene, a phylogenetic tree was calculated. It included sequences of the SILVA database and of the KSMP-Kiel marine fungal culture collection. Additionally contextual data about the habitat and the geographic origin were linked to each sequence of the tree. Most of the fungi belonged to the Ascomycota, followed by Basidiomycota, Chytridiomycota and basal fungi. Overall the tree is well supported by the current fungal phylogeny. The contextual data revealed differences in the distribution of the categories in the habitats, as well as in the geographic origins between the fungal sequences of the KSMP-Kiel culture collection and fungal sequences of the SILVA database. Additional aquatic-derived species were found in several orders, which were formerly not known from aquatic habitats. The sequences from the KSMP-Kiel culture collection revealed a strong impact on the tree due to five fungal species, that hitherto have not been related to aquatic environments. Not all orders of aquatic-derived fungi according to the current fungal phylogeny were present in the tree. The evaluation of the environmental data, linked to the phylogenetic tree, revealed some evidence for ecological signals and is awaiting further analyses