A reappraisal of Microthyriaceae and Micropeltidaceae

【摘要】：The Microthyriaceae and Micropeltidaceae are poorly known but interesting families. Microthyriaceae comprises 54 genera and Micropeltidaceae 27 genera, being of foliar epiphytes or saprobes on dead leaves and stems. We re-visited the two families based on examinations of generic types where possible. Members are distributed in Aulographaceae, Asterinaceae, Microthyriaceae, Micropeltidaceae and Palmulariaceae and notes are provided on each of these families. New sequence data for a number of species and genera are provided. Microthyriaceous members growing on other fungi and lichens differ from Microthyriaceae sensu stricto and the family Trichothyriaceae was reinstated to accommodate these taxa. The family Microthyriaceae is reduced to seven genera characterised by superficial, flattened thyriothecia, with the cells of the upper wall radiating in parallel arrangement from the distinct central ostiolar opening, while the lower peridium is generally poorly developed. The family Micropeltidaceae is reduced to eight genera. Sequence data is provided for five species with thyriothecia and Paramicrothyrium and Neomicrothyrium are described as new genera and Micropeltis zingiberacicola is introduced as a new species. Our phylogenetic analysis underscores the high genetic diversity for thyriotheciate species and there is no clear clade that can be well defined as Microthyriales. Nuclear ribosomal data support multiple polyphyletic lineages within Microthyriaceae and Micropeltidaceae. Some unexpected DNA based phylogenetic relationships such as those between Muyocopron and Saccardoella will require corroboration with more complete taxon sampling as well as additional non ribosomal markers.