1 research outputs found
Monilochaetes and allied genera of the Glomerellales, and a reconsideration of families in the Microascales
We examined the phylogenetic relationships of two species that mimic
Chaetosphaeria in teleomorph and anamorph morphologies,
Chaetosphaeria tulasneorum with a Cylindrotrichum
anamorph and Australiasca queenslandica with a Dischloridium
anamorph. Four data sets were analysed: a) the internal transcribed spacer
region including ITS1, 5.8S rDNA and ITS2 (ITS), b) nc28S (ncLSU) rDNA, c)
nc18S (ncSSU) rDNA, and d) a combined data set of ncLSU-ncSSU-RPB2 (ribosomal
polymerase B2). The traditional placement of Ch. tulasneorum in the
Microascales based on ncLSU sequences is unsupported and
Australiasca does not belong to the Chaetosphaeriaceae. Both
holomorph species are nested within the Glomerellales. A new genus,
Reticulascus, is introduced for Ch. tulasneorum with
associated Cylindrotrichum anamorph; another species of
Reticulascus and its anamorph in Cylindrotrichum are
described as new. The taxonomic structure of the Glomerellales is
clarified and the name is validly published. As delimited here, it includes
three families, the Glomerellaceae and the newly described
Australiascaceae and Reticulascaceae. Based on ITS and ncLSU
rDNA sequence analyses, we confirm the synonymy of the anamorph genera
Dischloridium with Monilochaetes. Consequently
Dischloridium laeënse, type species of the genus, and three
related species are transferred to the older genus Monilochaetes. The
teleomorph of D. laeënse is described in Australiasca
as a new species. The Plectosphaerellaceae, to which the anamorph
genus Stachylidium is added, is basal to the Glomerellales
in the three-gene phylogeny. Stilbella annulata also belongs to this
family and is newly combined in Acrostalagmus. Phylogenetic analyses
based on ncLSU, ncSSU, and combined ncLSU-ncSSU-RPB2 sequences clarify family
relationships within the Microascales. The family
Ceratocystidaceae is validated as a strongly supported monophyletic
group consisting of Ceratocystis, Cornuvesica,
Thielaviopsis, and the type species of Ambrosiella. The new
family Gondwanamycetaceae, a strongly supported sister clade to the
Ceratocystidaceae, is introduced for the teleomorph genus
Gondwanamyces and its Custingophora anamorphs. Four families
are accepted in the Microascales, namely the
Ceratocystidaceae, Gondwanamycetaceae,
Halosphaeriaceae, and Microascaceae. Because of a suggested
affinity of a Faurelina indica isolate to the Microascales,
the phylogenetic position of the Chadefaudiellaceae is reevaluated.
Based on the results from a separate ncLSU analysis of the
Dothideomycetes, Faurelina is excluded from the
Microascales and placed in the Pleosporales