Pleosporales - CBS - KNAW

Fungal Diversity
tentatively described the generic type of W. gigantospora
as a representing of the type of W. gigaspora here.
New family names, i.e. Pseudosphaeriaceae and Wettsteininaceae
(as Wettsteiniaceae) and a new order, Pseudosphaeriales
had been introduced to accommodate Wettsteinina and
its synonym Pseudosphaeria (Höhnel 1907; Locquin 1972).
After a systematic study, Wettsteinina was included in
Pleosporaceae basedonits“Pleospora-type” centrum, and
Pseudosphaeriaceae and Wettsteininaceae are treated as
synonyms of Pleosporaceae (Shoemaker and Babcock 1987).
Phylogenetic study
Wettsteinina macrotheca (Rostr.) E. Müll., W. pachyasca
(Niessl) Petr. and W. dryadis (Rostr.) Petr. were reported to be
closely related to Pleomassaria siparia (Melanommataceae)
(Kodsueb et al. 2006a), and W. lacustris (Fuckel) Shoemaker
& C.E. Babc. nested within Lentitheciaceae (Schoch et al.
2009). The generic type has not been sequenced.
Concluding remarks
The most striking character for Wettsteinina is its
asymmetrical ascospores, thick-walled obpyriform asci
and lack of pseudoparaphyses at maturity. These
characters are comparable with genera in the Capnodiales
and Venturiales. The phylogenetic significance of
these characters are not fully understood, while the
hemibiotrophic or saprobic life style may indicate its
polyphyletic nature (Shoemaker and Babcock 1987).
Strains from the genus, in particular the generic type
require DNA sequence data so that the phylogenetic
placement can be investigated.
Wilmia Dianese, Inácio & Dorn. -Silva, Mycologia 93:
1014 (2001). (Phaeosphaeriaceae)
Generic description
Habitat terrestrial, hemibiotrophic or biotrophic. Ascomata
small, scattered, immersed, globose to subglobose, papillate.
Peridium thin, composed of a few layers of brown, thickwalled
cells of textura angularis to prismatica. Hamathecium
comprising filliform, septate, rarely branching, evanescent,
cellular pseudoparaphyses embedded in mucilage. Asci
bitunicate, fissitunicate, cylindrical to clavate, with a short,
furcate pedicel and ocular chamber. Ascospores fusoid, pale
brown, 1-septate.
Anamorphs reported for genus: see below.
Literature: Dianese et al. 2001.
Type species
Wilmia brasiliensis Dianese, Inácio & Dorn.-Silva, Mycologia
93: 1014 (2001). (Fig. 96)
Ascomata 175–240 μm high×95–145 μm diam., scattered,
immersed, globose to subglobose; apex with a short
papilla, 40–80 μm long, ostiolate, periphysate, periphyses
up to 90 μm long (Fig. 96a and b). Peridium 6–15 μm
wide, 1-layered, composed of 3–7 layers of brown, thickwalled
cells of textura angularis to prismatica, cells 4–
9 μm diam., cell wall 2–4 μm thick (Fig. 96a and b).
Hamathecium of long cellular pseudoparaphyses 2–3 μm
broad, septate, rarely branching, embedded in mucilage,
evanescent. Asci 65–95×9.5–14 μm (x ¼ 78:5 11:5mm,
n=10), 8-spored, bitunicate, fissitunicate, cylindrical to
clavate, with a short, furcate pedicel and a small ocular
chamber (Fig. 96c, d and f). Ascospores 22.5–28×5–
8.5 μm (x ¼ 26:5 6:8mm, n=10), biseriate, fusoid with
narrowly rounded ends, pale brown, 1-septate, constricted
at the septum, the upper cell often shorter and broader than
the lower one, smooth, with or without sheath (Fig. 96d and
e).
Anamorph: Conidiomata 170–200 μm high×85–130 μm
diam., eustromatic, immersed, subglobose to irregular,
ostiolate, brown. Peridium thin, 1–2 walllayers,6–8 μm
thick, thicker near the apex. Ostiole 50–63 μm high×30–35
broad. Conidiogenous cells ampulliform or lageniform,
phialidic, aseptate. Conidia 13–20×4–7 μm, ellipsoid,
oblong, ovoid, hyaline (Dianese et al. 2001).
Material examined: BRAZIL, Distrito Federal, Vargem
Bonita, Fazenda Agua Limpa, on leaves of Memora
pedunculata (Vell.) Miers, 18 May 1995, Carlos A. Inácio
(UB Col. Microl 8438 holotype).
Notes
Morphology
Wilmia was formally established by Dianese et al. (2001)
as a monotypic genus represented by W. brasiliensis, which
causes leaf spots on Memora pedunculata. The peridium of
W. brasiliensis comprises a few layers of brown, thickwalled
textura angularis to prismatica cells, and it also has
cellular pseudoparaphyses, clavate asci, 1-septate pale
brown ascospores (Dianese et al. 2001).
Phylogenetic study
None.
Concluding remarks
The dicotyledonous host habit of Wilmia brasiliensis seems
in agreement with Leptosphaeriaceae rather than Phaeosphaeriaceae.
But a verified conclusion can only be reached by
further molecular phylogenetic study.
Xenolophium Syd., Bulletin of the Bernice P. Bishop
Museum, Honolulu, Hawaii 19: 96 (1925). (Pleosporales,
genera incertae sedis)