Evidence for the polyphyly of Encoelia and Encoelioideae with reconsideration of respective families in Leotiomycetes

Abstract

This study focuses on the genus Encoelia and the subfamily Encoelioideae in the morphologically and ecologically diverse Helotiales. The 28S and 18S rDNA as well as tef1, rpb1 and rpb2 were sequenced for 70 species. Phylogenetic analyses revealed Encoelia and Encoelioideae to be highly polyphyletic, with species distributed among eight major lineages. Encoelia fascicularis and E. pruinosa belonged to Sclerotiniaceae and were combined in a new genus, Sclerencoelia. Rutstroemiaceae comprised E. tiliacea and Dencoeliopsis johnstonii, both accepted in Rutstroemia. The type of Encoelia, E. furfuracea, was closely related to species of Velutarina, Cenangiopsis and Crumenulopsis. These species together with members of Hemiphacidiaceae formed a clade conforming to the emended concept of Cenangiaceae, introduced here. Another resurrected family, Cordieritidaceae, comprised E. fimbriata, E. heteromera and species of Ameghiniella, Cordierites, Diplocarpa and Ionomidotis, characterised by inamyloid asci and a positive ionomidotic reaction. Encoelia glauca showed closest affinities with Chlorociboria species in Chlorociboriaceae. A new genus, Xeropilidium, with sporodochial and pycnidial synanamorphs, was described for the distinct encoelioid member of the Chaetomellaceae, previously known as E. fuckelii. Morphological and ecological synapomorphies were distinguished from convergent characters to delimit monophyletic taxa including encoelioid fungi. Incorporation of public sequences from various biological samples in ITS rDNA analyses allowed identification of sequenced organisms at species, genus, or family level and added information on the ecology of seversal taxa. Members of Cenangiaceae appeared to be widespread as endophytes. Inclusion of encoelioid genera in Chaetomellaceae and Sclerotiniaceae added xylicolous saprotrophs to these families.