Multilocus phylogeny- and fruiting feature-assisted delimitation of EuropeanCyclocybe aegeritafrom a new Asian species complex and related species

Cyclocybe aegerita(synonym:Agrocybe aegerita) is a widely cultivated edible and reportedly almost cosmopolitan mushroom species that serves as a model fungus for basidiome formation and as producer of useful natural products and enzymes. Focusing on strains from different continents, here, we present a phylogenetic analysis of this species and some adjacent taxa that employs four phylogenetic markers. In addition, we tested the strains' capability to fructify on agar media. Our analysis reveals that "C. aegerita sensu lato" splits up into the following two well-supported monophyletic geographic lineages: a European clade and an Asian clade. The European one is closely associated with the Chinese speciesCyclocybe salicaceicola. In contrast, the Asian lineage, which we preliminarily designate asCyclocybe chaxinguagg., may comprise several species (species complex) and clusters with the Pacific speciesCyclocybe parasitica(New Zealand). In addition, fruiting properties differ acrossC. aegeritaand its Asian and Pacific relatives; however, strains from the Asian clade andC. parasiticatend to form larger basidiomes with relatively big caps and long stipes and strains from the European clade exhibit a more variable fruiting productivity with the tendency to form more basidiomes, with smaller caps and shorter stipes. Moreover, some strains showed individual fruiting patterns, such as the preference to fruit where they were exposed to injuring stimuli. In conclusion, the delimitation of the newly delimited Asian species complex from our multilocus phylogeny of "C. aegerita sensu lato", which is supported by phenotypic data, depicts an exemplary case of biogeographic diversity within a previously thought homogeneous species of near worldwide distribution.