Pleosporales - CBS - KNAW

Fungal Diversity
and Sydow 1918). Luttrell (1955) introduced the Pleosporales
(lacking a Latin description), which is characterized by
its Pleospora-type of centrum development. Based on this,
the Pleosporaceae and the Lophiostomataceae as well as
other five families were placed in Pleosporales (Luttrell
1955). Pleosporaceae is the largest and most typical family
in Pleosporales. Wehmeyer (1975) stated that the Pleosporatype
centrum development is verified in a small number of
genera, and centrum development in the majority of genera
is unknown; thus the placement of families or genera is quite
arbitrary. In addition, the circumscription of Pleosporaceae
is not clear-cut, and “……ascostromata of many different
types, which are previously placed in various other families
(Trichosphaeriaceae, Melanommataceae, Cucurbitariaceae,
Amphisphaeriaceae etc.) are to be found here” (Wehmeyer
1975). Thus, the heterogeneous nature of Pleosporales is
obvious (Eriksson 1981), and had been confirmed by
subsequent molecular phylogenetic studies (e.g. Kodsueb et
al. 2006a). Based on the multi-gene phylogenetic analysis,
some species from Lewia, Cochliobolus, Pleospora, Pyrenophora
and Setosphaeria resided in the Pleosporaceae
(Zhang et al. 2009a).
Sporormiaceae Munk 1957
The Sporormiaceae is the largest coprophilous family in
Pleosporales, which bears great morphological variation.
Ascomata vary from cleistothecoid to perithecoid, asci are
regularly or irregularly arranged, clavate or spherical,
ascospores with or without germ slits or ornamentations.
Based on phylogenetic analysis, Sporormiaceae is most
likely monophyletic as currently circumscribed (Kruys et al.
2006; Kruys and Wedin 2009).
?Teichosporaceae M.E. Barr 2002
The Teichosporaceae was introduced by segregating some
non-lichenized members of the Dacampiaceae which are
apostrophic on woody stems and periderm or hypersaprotrophic
on other ascomycetous fungi (Barr 2002). The Dacampiaceae
together with its synonym, Pyrenidiaceae was only
maintained to accommodate its lichenicolous genera (Barr
2002). This proposal does not have any molecular phylogenetic
support.
Tetraplosphaeriaceae Kaz. Tanaka & K. Hirayama 2009
The Tetraplosphaeriaceae was introduced to accommodate
five genera, i.e. Tetraplosphaeria, Triplosphaeria,
Polyplosphaeria and the anamorphic genera Pseudotetraploa
and Quadricrura (Tanaka et al. 2009). The Tetraplosphaeriaceae
is characterized by its Massarina-like
teleomorphs and its Tetraploa-like anamorphs with setaelike
appendages, and its monophylogenetic status has been
recently confirmed based on DNA phylogenetic studies
(Tanaka et al. 2009).
Trematosphaeriaceae
Three species, viz. Falciformispora lignatilis, Halomassarina
thalassiae and Trematosphaeria pertusa form a
robust clade, which forms a sister group with other
pleosporalean families (Schoch et al. 2009; Suetrong et al.
2009). Trematosphaeriaceae is waiting to be formally
proposed (Suetrong et al. data unpublished).
?Zopfiaceae G. Arnaud ex D. Hawksw. 1992
The Zopfiaceae was introduced by Arnaud (1913), but
was invalid due to the lack of a Latin diagnosis (see
comments by Eriksson and Hawksworth 1992). The Zopfiaceae
was formally introduced by Eriksson and Hawksworth
(1992), and is characterized by its cleistothecial ascomata,
thick-walled peridium, globose or saccate asci and oneseptate,
dark brown ascospores (Cannon and Kirk 2007).
Currently, eleven genera are included, but the family is likely
polyphyletic (Kruys et al. 2006).
Excluded family
Phaeotrichaceae Cain 1956
The cleistothecioid ascomata, ascospores with germ pore
at each end and the absence of pseudoparaphyses indicate
that the Phaeotrichaceae may not be closely related to
Pleosporales. This was confirmed by DNA based phylogenies
(Schoch et al. 2009). Thus, we exclude it from
Pleosporales.
Final remarks
Problems and concerns
Recently, many new pleosporalean lineages from freshwater
(Shearer et al. 2009; Zhang et al. 2009a), marine
(Suetrong et al. 2009) or from bambusicolous hosts (Tanaka
et al. 2009) have been reported. In particular, large-scale
phylogenetic analysis indicate that numerous unresolved
clades still exist, which may also indicate that a large
number of fungal lineages are not resolved. As has been
estimated, 95% of all fungi are unreported (Hawksworth
1991), and a large portion of them might exist only as
hyphae (or DNA-only fungi, Taylor 1993). Under the
influence of human activities, environmental situations are
changing quickly, which may result in numerous fungal
taxa losing their habitats and/or become endangered. More
field work is urgently needed.
A future polyphasic approach to study Pleosporales
The use of DNA sequence comparisons have proved
invaluable in modern concepts of fungal taxonomy. It is now
clear many fungi do not produce reproductive structures or