Pleosporales - CBS - KNAW

Fungal Diversity
upper place, septate pseudoparaphyses, embedded in
mucilage, anastomosing and branching between and
above the asci (Fig. 51f). Asci 110–145×10–15 μm
(x ¼ 127:5 13mm, n=10), 8-spored, bitunicate, fissitunicate
(ectotunica no constriction), cylindro-clavate, with a
furcate pedicel and a small ocular chamber (to 1.5 μm wide×
2 μm high) (J-) (Fig. 51c, d and e). Ascospores 27–38(−43)×
5–7.5 μm (x ¼ 31:2 6:4mm, n=10), biseriate, fusoid,
curved, hyaline, usually 1-septate, with 3–5 septaandfaintly
brown when old, with (2-)3(−4) distinct oil drops in each cell
and short terminal appendage at ends (Fig. 51h, i and j), and
ornamented with warts when spores are senescent (Fig. 51g).
Anamorph: none reported.
Material examined: SWEDEN, Smaland, Femsjö par.,
Femsjö, on Prunus, 2006, Elias Fries, det. Geir Mathiassen
(UPS, lectotype, asSphaeria macrostoma Fr.). FRANCE,
Ariège, Rimont, Las Muros, on dead stems of Vitis vinifera,
2 Sept. 1996 (IFRD2005).
Notes
Morphology
Lophiostoma is morphologically a well studied genus
(Barr 1990a; Chesters and Bell 1970; Holm and Holm
1988; Mugambi and Huhndorf 2009b; Yuan and Zhao
1994), and currently it comprises about 30 species (Tanaka
and Harada 2003b). The genus was characterized as
having immersed to erumpent ascomata with a cylindrical
or crest-like papilla and full length, slit-like ostiole; a
peridium of unequal thickness, which was broader near the
base (Lophiostoma-type); mostly clavate, bitunicate asci
and 1- to several septate, hyaline to pigmented ascospores
with terminal appendages or surrounded by a mucilaginous
sheath (Holm and Holm 1988). This definition was
followed by Barr (1990a), Yuan and Zhao (1994) and
Hyde et al. (2002).
The crest-like papilla has been regarded as a prominent
morphological character of Lophiostoma macrostomum
(Chesters and Bell 1970; Holm and Holm 1988). In the
lectotype specimen, the raised area above the ascomata is
up to 300 μm high and 480 μm long, and seen as a
flattened or even Y-shaped crest (Fig. 51a). In Lophiostoma
curtum (Fr.) De Not. and Lophiotrema boreale Math. the
raised area above the ascomata varies considerably in
height or is even lacking (Holm and Holm 1988). Thus
the variable “crest-like raised area in Lophiostomataceae”
was explained as an evolutionarily adaptation to the hard
substrate within which the ascomata develop (Holm and
Holm 1988). The ascospores of L. macrostomum usually
turn reddish brown when mature, and minutely verrucose
ornamentation was also found on the surface of the
pigmented ascospores. Hyaline ascospores that became
pigmented with age are common in Lophiostoma, such as
in L. appendiculatum Fuckel, L. massarioides (Sacc.) L.
Holm & K. Holm, L. semiliberum, L. subcorticale Fuckel
and L. winteri (Holm and Holm 1988; Tanaka and Harada
2003b). The phylogenetic significance of this character
should be observed carefully in the future but at present its
phylogenetic significance is unclear as this also occurs in
some Lophiotrema species.
Phylogenetic study
Phylogenetic affinity with some Massarina species has
been reported by Liew et al. (2002), and several Massarina
species were transferred into Lophiostoma. Inasystematic
study of Lophiostoma- and Massarina-related fungi conducted
by Zhang et al. (2009b), Lophiostoma taxa clustered
into two groups; one includes the type species L. macrostomum
with crest-like ostioles, L. rugulosum Yin. Zhang, J.
Fourn. & K.D. Hyde with a wide, umbilicate pore surrounded
by 4–6 radial ridges, and L. glabro-tunicatus with small
ostiolar pores; the other cluster comprises Lophiostoma-like
taxa with slot-like ostioles lacking raised crests, which
includes L. arundinis (Pers.) Ces. & De Not., L. caulium, L.
compressum (Pers.) Ces. & De Not., L. crenatum (Pers.)
Fuckel, L. fuckelii (Sacc.) Sacc., L. macrostomoides, L.
semiliberum and L. viridarium Cooke, which seems to
represent a natural group at the family level. This conclusion
is tentative until verified sequences of L. macrostomum are
included in analyses (see comments of Zhang et al. 2009a).
Concluding remarks
We tend to accept a narrow concept of Lophiostomataceae,
which only comprises species of Lophiostoma sensu
stricto (Zhang et al. 2009a).
Lophiotrema Sacc., Michelia 1: 338 (1878). (Pleosporales,
genera incertae sedis)
Generic description
Habitat terrestrial, saprobic. Ascomata small- to mediumsized,
with or without short papilla. Hamathecium of dense,
long, septate pseudoparaphyses, anastomosing and branching
between and above asci. Asci cylindrical to cylindroclavate.
Ascospores hyaline, 1–3-septate, usually with
mucilaginous sheath.
Anamorphs reported for genus: none.
Literature: Barr 1990a; Chesters and Bell 1970; Holm and
Holm 1988; Saccardo 1878a; Tanaka and Harada 2003c;
Tang et al. 2003; Yuan and Zhao 1994.
Type species
Lophiotrema nucula (Fr.) Sacc., Michelia 1: 338 (1878).
(Fig. 52)