Abstract
A reappraisal of the phylogenetic integrity of bitunicate ascomycete fungi
belonging to or previously affiliated with the Hysteriaceae,
Mytilinidiaceae, Gloniaceae and Patellariaceae is
presented, based on an analysis of 121 isolates and four nuclear genes, the
ribosomal large and small subunits, transcription elongation factor 1 and the
second largest RNA polymerase II subunit. A geographically diverse and high
density taxon sampling strategy was employed, including multiple
isolates/species from the following genera: Anteaglonium (6/4),
Encephalographa (1/1), Farlowiella (3/1),
Gloniopsis (8/4), Glonium (4/2), Hysterium (12/5),
Hysterobrevium (14/3), Hysterographium (2/1),
Hysteropatella (2/2), Lophium (4/2), Mytilinidion
(13/10), Oedohysterium (5/3), Ostreichnion (2/2),
Patellaria (1/1), Psiloglonium (11/3), Quasiconcha
(1/1), Rhytidhysteron (8/3), and 24 outgroup taxa. Sequence data
indicate that although the Hysteriales are closely related to the
Pleosporales, sufficient branch support exists for their separation
into separate orders within the Pleosporomycetidae. The
Mytilinidiales are more distantly related within the subclass and
show a close association with the Gloniaceae. Although there are
examples of concordance between morphological and molecular data, these are
few. Molecular data instead support the premise of a large number of
convergent evolutionary lineages, which do not correspond to previously held
assumptions of synapomorphy relating to spore morphology. Thus, within the
Hysteriaceae, the genera Gloniopsis, Glonium,
Hysterium and Hysterographium are highly polyphyletic. This
necessitated the transfer of two species of Hysterium to
Oedohysteriumgen. nov. (Od. insidenscomb.
nov. and Od. sinense comb. nov.), the description of a new
species, Hysterium barrianumsp. nov., and the transfer of
two species of Gloniopsis to Hysterobreviumgen.
nov. (Hb. smilaciscomb. nov. and Hb.
constrictumcomb. nov.). While Hysterographium, with
the type Hg. fraxini, is removed from the Hysteriaceae, some
of its species remain within the family, transferred here to
Oedohysterium (Od. pulchrumcomb. nov.),
Hysterobrevium (Hb. moricomb. nov.) and
Gloniopsis (Gp. subrugosacomb. nov.); the latter
genus, in addition to the type, Gp. praelonga, with two new species,
Gp. arciformissp. nov. and Gp. kenyensis sp. nov.
The genus Glonium is now divided into Anteaglonium
(Pleosporales), Glonium (Gloniaceae), and
Psiloglonium (Hysteriaceae). The hysterothecium has evolved
convergently no less than five times within the Pleosporomycetidae
(e.g., Anteaglonium, Farlowiella, Glonium,
Hysterographium and the Hysteriaceae). Similarly,
thin-walled mytilinidioid (e.g., Ostreichnion) and patellarioid
(e.g., Rhytidhysteron) genera, previously in the
Mytilinidiaceae and Patellariaceae, respectively,
transferred here to the Hysteriaceae, have also evolved at least
twice within the subclass. As such, character states traditionally considered
to represent synapomorphies among these fungi, whether they relate to spore
septation or the ascomata, in fact, represent symplesiomorphies, and most
likely have arisen multiple times through convergent evolutionary processes in
response to common selective pressures.
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