Pleosporales - CBS - KNAW

Fungal Diversity
substrates and many occur in freshwater or has been
isolated from air. The polyphyletic nature of T. aristata
has been well documented (Tanaka et al. 2009). Anamorphic
stages can serve as a diagnostic character for this
family.
Diademaceae, Massariaceae, Sporormiaceae
and Teichosporaceae
The Sporormiaceae is coprophilous having Phoma or
Phoma-related anamorphic states (Cannon and Kirk 2007).
Comoclathris (Diademaceae) is linked with Alternaria-like
anamorphs (Simmons 1952). Myxocyclus links to Massaria
(Massariaceae) (Hyde et al. 2011). The anamorphic stage of
Chaetomastia (Teichosporaceae) isAposphaeria- orConiothyrium-like
(Barr 1989c).
Generally speaking, the morphologically simple conidiophores
are usually considered phylogenetically uninformative
(Seifert and Samuels 2000). Phoma-like anamorphs commonly
occur in Pleosporales, while their colorless and unicellular
conidia are also not phylogenetically informative (Seifert and
Samuels 2000).
All of the above mentioned anamorphic taxa of
Pleosporales have phialidic, annellidic or sympodial conidiogenous
cells, representing apical wall-building type
(compared to ring wall-building and diffused wallbuilding)
(Nag Raj 1993), which may indicate that the
wall-building type probably has phylogenetic significance.
Molecular phylogeny of Pleosporales
Numerous genes have been applied in phylogenetic
studies of Pleosporales, mostly including LSU, SSU,
mtSSU and ITS as well as the protein genes, such as
RPB1, RPB2, TEF1, β-tubulin (TUB1) and actin (ACT1).
A single gene such as ITS or LSU, has been used to study
phylogenetic relationships between Leptosphaeria and
Phaeosphaeria (Câmara et al. 2002) or Pleosporaceae
and Tubeufiaceae (Kodsueb et al. 2006a, b) (Table2). The
use of these phylogenetic markers, although making
important contributions, has not been successful in
resolving numerous relationships in single gene dendrograms.
One exception is the use of SSU sequences to
demonstrate the phylogenetic significance of pseudoparaphyses
(Liew et al. 2000) whilst rejecting the phylogenetic
utility of pseudoparaphyses morphology (cellular or
trabeculate). Analyses with combined genes have had
more success. For instance combined analyses with LSU
and SSU sequence data could be used to define family
level classification in a few cases (Dong et al. 1998; de
Gruyter et al. 2009; Lumbsch and Lindemuth 2001; Pinnoi
et al. 2007; Zhang et al. 2009b) (Table2). The addition of
more than two genes has been used to determine relationships
between orders. For instance, genes such as LSU,
SSU and mtSSU have been used to analyze ordinal
relationships in Loculoascomycetes (Lindemuth et al.
2001), and to analyze phylogenetic relationships of
coprophilous families in Pleosporales (Kruys et al.
2006). Phaeocryptopus gaeumannii (T. Rohde) Petr. was
showntobelonginDothideales based on LSU, SSU and
ITS sequence analysis (Winton et al. 2007), while Schoch
et al. (2006) used four genes, i.e. LSU, SSU, RPB2 and
TEF1 to evaluate the phylogenetic relationships among
different orders of the Dothideomycetes. Fivegenes,viz.
LSU, SSU, TEF1, RPB1 andRPB2, were used to study the
phylogenetic relationships of different orders within
Dothideomycetes (Schoch et al. 2009) and of different
families within Pleosporales (Zhang et al. 2009a)
(Table 2). It is clear that even more genes will be required
to address the remaining issues and the promise of genome
analyses is within reach (www.jgi.doe.gov/sequencing/
why/dothideomycetes.html) forDothideomycetes.
The importance of generic type specimens
The type specimen (collection type) is a fundamental
element in the current Code of Botanical Nomenclature at
familial or lower ranks (Moore 1998). A type specimen
fixes the name to an exact specimen at family, genera,
species and variety/subspecies rank and is ultimately based
on this single specimen, i.e. a family name is based on a
genus, the genus name is based on a species, and the
species name is based on a specimen (Kirk et al. 2008).
The generic type is of great importance in defining
generic circumscriptions in fungal taxonomy. The generic
types of Pleosporales have been studied previously by
many mycologists. For instance, Müller and von Arx
(1962) studied the generic types of “Pyrenomycetes”, and
described and illustrated them in detail. Sivanesan (1984)
described and illustrated the generic representatives of
Loculoascomycetes for both their teleomorphs and anamorphs,
and their links were emphasized. A large number
of pleosporalean genera have been studied by Barr (1990a,
b). Almost all of the previous work was conducted more
than 20 years ago, when no molecular phylogenetic studies
could be carried out and thus had been carried out in a
systematic fashion.
Aim and outline of present study
The present study had two principal objectives:
1. To explore genera under Pleosporales based on the
generic types and provide a detailed description and
illustration for the type species of selected genera,
discuss the study history of those genera, and explore
their ordinal, familial, and generic relationships;