59 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
An overview of the taxonomy, phylogeny, and typification of nectriaceous fungi in Cosmospora, Acremonium, Fusarium, Stilbella, and Volutella
A comprehensive phylogenetic reassessment of the ascomycete genus
Cosmospora (Hypocreales, Nectriaceae) is undertaken using
fresh isolates and historical strains, sequences of two protein encoding
genes, the second largest subunit of RNA polymerase II (rpb2), and a
new phylogenetic marker, the larger subunit of ATP citrate lyase
(acl1). The result is an extensive revision of taxonomic concepts,
typification, and nomenclatural details of many anamorph- and
teleomorph-typified genera of the Nectriaceae, most notably
Cosmospora and Fusarium. The combined phylogenetic analysis
shows that the present concept of Fusarium is not monophyletic and
that the genus divides into two large groups, one basal in the family, the
other terminal, separated by a large group of species classified in genera
such as Calonectria, Neonectria, and Volutella. All accepted
genera received high statistical support in the phylogenetic analyses.
Preliminary polythetic morphological descriptions are presented for each
genus, providing details of perithecia, micro- and/or macro-conidial
synanamorphs, cultural characters, and ecological traits. Eight species are
included in our restricted concept of Cosmospora, two of which have
previously documented teleomorphs and all of which have
Acremonium-like microconidial anamorphs. A key is provided to the
three anamorphic species recognised in Atractium, which is removed
from synonymy with Fusarium and epitypified for two macroconidial
synnematous species and one sporodochial species associated with waterlogged
wood. Dialonectria is recognised as distinct from Cosmospora
and two species with teleomorph, macroconidia and microconidia are accepted,
including the new species D. ullevolea. Seven species, one with a
known teleomorph, are classified in Fusicolla, formerly considered a
synonym of Fusarium including members of the F. aquaeductuum
and F. merismoides species complex, with several former varieties
raised to species rank. Originally a section of Nectria,
Macroconia is raised to generic rank for five species, all producing
a teleomorph and macroconidial anamorph. A new species of the
Verticillium-like anamorphic genus Mariannaea is described
as M. samuelsii. Microcera is recognised as distinct from
Fusarium and a key is included for four macroconidial species, that
are usually parasites of scale insects, two of them with teleomorphs. The four
accepted species of Stylonectria each produce a teleomorph and micro-
and macroconidial synanamorphs. The Volutella species sampled fall
into three clades. Pseudonectria is accepted for a perithecial and
sporodochial species that occurs on Buxus. Volutella s. str.
also includes perithecial and/or sporodochial species and is revised to
include a synnematous species formerly included in Stilbella. The
third Volutella-like clade remains unnamed. All fungi in this paper
are named using a single name system that gives priority to the oldest generic
names and species epithets, irrespective of whether they are originally based
on anamorph or teleomorph structures. The rationale behind this is
discussed
Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs
A new pleosporalean family Tetraplosphaeriaceae is established to
accommodate five new genera; 1) Tetraplosphaeria with small ascomata
and anamorphs belonging to Tetraploa s. str., 2)
Triplosphaeria characterised by hemispherical ascomata with rim-like
side walls and anamorphs similar to Tetraploa but with three conidial
setose appendages, 3) Polyplosphaeria with large ascomata surrounded
by brown hyphae and anamorphs producing globose conidia with several setose
appendages, 4) Pseudotetraploa, an anamorphic genus, having
obpyriform conidia with pseudosepta and four to eight setose appendages, and
5) Quadricrura, an anamorphic genus, having globose conidia with one
or two long setose appendages at the apex and four to five short setose
appendages at the base. Fifteen new taxa in these genera mostly collected from
bamboo are described and illustrated. They are linked by their Tetraploa
s. l. anamorphs. To infer phylogenetic placement in the
Pleosporales, analyses based on a combined dataset of small- and
large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out.
Tetraplosphaeriaceae, however, is basal to the main pleosporalean
clade and therefore its relationship with other existing families was not
completely resolved. To evaluate the validity of each taxon and to clarify the
phylogenetic relationships within this family, further analyses using
sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α
(TEF), and β-tubulin (BT), were also conducted. Monophyly of the family
and that of each genus were strongly supported by analyses based on a combined
dataset of the three regions (ITS+TEF+BT). Our results also suggest that
Tetraplosphaeria (anamorph: Tetraploa s. str.) is an
ancestral lineage within this family. Taxonomic placement of the bambusicolous
fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina,
Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and
Versicolorisporium, are also discussed based on the SSU+LSU
phylogeny
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