Early-diverging fungal phyla: taxonomy, species concept, ecology, distribution, anthropogenic impact, and novel phylogenetic proposals

Abstract

The increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved. In this article, we review the recent taxonomy of the basal fungi and re-evaluate the relationships among early-diverging lineages of fungal phyla. We also provide information on the ecology and distribution in Mucoromycota and highlight the impact of chytrids on amphibian populations. Species concepts in Chytridiomycota, Aphelidiomycota, Rozellomycota, Neocallimastigomycota are discussed in this paper. To preserve the current application of the genus Nephridiophaga (Chytridiomycota: Nephridiophagales), a new type species, Nephridiophaga blattellae, is proposed.

Phylogenomics unravels the early diversification of fungi

“…Thus, Microsporidia and Rozellomycota form two distinct lineages for which a frequently discussed paraphyly 6,22,25 cannot be confirmed here. Whether or not Microsporidia + Rozellomycota should be classified as only one phylum is currently debated 6,31,38 and will require data from additional representatives of Rozellomycota.…”

“…Glomeromycota were suggested to form an independent phylum at the beginning of this century 29 , but closer phylogenetic affiliation has remained controversial ever since 12,25,30,31 . A sister-relationship to the Dikarya has been proposed based on tree inferences using the elongation factor EF-1 alpha, RNA polymerase II subunits and/or rRNA gene alignments 6,29,[31][32][33] . This placement was discussed to be artificial due to lineage-specific rates in these data sets 12 and was rejected in a ML tree inference from a 192-protein matrix.…”

“…, which live either as saprophytes, parasites, or as intermediate forms, but also regarding the discussed branching order among its phyla 6,12,30 . With that, however, the justification for the separation of the chytridiomycete phylum "Caulochytriomycota" from the Chytridiomycota remains enigmatic (the erection of this phylum was proposed by Doweld in 2014 39 and has been adapted by other researchers since).…”

“… Summary Phylogenomic analyses have boosted our understanding of the evolutionary trajectories of all living forms by providing continuous improvements to the tree of life 1–5 . Within this tree, fungi represent an ancient eukaryote group 6 , having diverged from the animals ∼1.35 billion years ago 7 . Estimates of the number of extant species range between 1.5 and 3.8 million 8,9 .…”

Discovery of Three New Mucor Species Associated with Cricket Insects in Korea

“…The genus Mucor was described by Fresenius [ 1 ], and it is classified in the family Mucoraceae , order Mucorales , and phylum Mucoromycota , which belongs to the early diverging fungi [ 2 ]. With more than 90 currently accepted species [ 3 , 4 , 5 , 6 , 7 , 8 ], Mucor is the largest genus within the Mucorales .…”