Leaf-inhabiting genera of the Gnomoniaceae, Diaporthales - CBS

Le a f-i n h a b i t i n g g e n e r a o f t h e Gn o m o n i a c e a e, Di a p o r t h a l e s
brown. Colonies on MEA attaining 60 mm diam after 40 d at 23 °C,
flat, pale brown to dark brown, smooth with scant aerial mycelium;
margin diffuse, wavy; reverse pale brown to dark brown. Colonies
on MYA attaining 40 mm after 40 d at 23 °C, flat or radially furrowed,
greyish brown or pale brown to dark brown, velvety, with scant
droplets of clear exudate; margin well-defined, even or broadly
wavy; reverse dark brown. Cultures incubated at 2/10 °C dark/light
regime produce sterile perithecia after 4.5 mo on MEA and MYA but
not on PDA. Perithecia remain sterile.
Habitat: On overwintered fallen or hanging leaves of Corylus
californica (A. DC.) Rose (Betulaceae).
Distribution: Canada (British Columbia) and U.S.A. (WA).
Holotype: U.S.A., Washington, Mason Co., Potlatch State Park,
next to U.S. route 101, on overwintered fallen leaves, 16 May 2006,
M.V. Sogonov MS0364 (BPI 877465A, ex-type culture AR 4287 =
CBS 121246) GenBank EU254786.
Additional specimens examined: Canada, British Columbia, Vancouver Island,
Goldstream Provincial Park, on veins of overwintered but still hanging leaves, 11
May 2006, M.V. Sogonov MS0408b (BPI 877526C, culture AR 4336 = CBS 121265);
U.S.A., Washington, Mason Co., Potlatch State Park, on overwintered leaves, 16
May 2006, M.V. Sogonov MS0363 (BPI 877466A, culture AR 4285 = CBS 121244).
Notes: Specimens previously identified as Gnomonia gnomon on
Corylus in North America may actually be G. neognomon or G.
pendulorum.
Gnomonia orcispora Sogonov, sp. nov. MycoBank MB 512164.
Figs 5C–H; 6D–F; 7P–X.
Perithecia 150–280 µm alta × 160–310 µm diam. Rostrum usque
ad 350 µm longum, basi 32–42 µm diam, apice 24–29 µm diam.
Ascosporae ovales, inaequilaterae, (14–)15.5–17.5(–19.5) × (4.5–)
5–5.5(–6) µm. Ad plerumque Gnomoniae speciebus ascosporae
longitudine latitudineque differt. Ascosporae longitudo latitudoque
similares G. ostryae, sed ascosporis in extremitatibus hilo terminatis
et guttulis majoribus in ascosporae cellulis differt. Holotypus: BPI
877465C.
Anamorph: Unknown.
Etymology: Refers to the appearance of spores from Latin orca
(barrel-shaped) and spora (spore).
Perithecia solitary, without stroma, hypophyllous, loosely scattered
on blades and veins, immersed at first, erumpent at maturity, black,
spherical when moist, 150–280 µm high × 160–310 µm diam,
concave when dry. Necks marginal, straight or slightly sinuous,
absent at ascospore formation, growing at maturity of ascospores,
reaching 350 µm long, 32–42 µm wide at base, 24–29 µm wide
at apex. Asci oval to fusiform, (53–)58.5–62.5(–69.5) × (19.5–)
20–20.5(–22) µm (mean = 61 × 20.5, SD 5.9, 0.9, n=5), apical
ring 5–5.5 µm diam, with eight ascospores with eight ascospores
evenly or slightly unevenly parallel. Ascospores oval, inequilateral,
(14–)15.5–17.5(–19.5) × (4.5–)5–5.5(–6) µm (mean = 16.5 × 5, SD
1.1, 0.4, n=45), l:w (2.8–)3–3.3(–3.7) (mean = 3.2, SD 0.2, n=45),
two-celled, constricted at septum, septum located at (54–)59–63(–
66) % (mean = 61, SD 3, n=45) of ascospore length, ends blunt,
rounded or somewhat truncated, each cell with two large guttules;
appendages navicular, large to 15 μm long, 8 μm wide but very thin
and often indistinct, with base surrounded by a pronounced hilum
on ascospore wall.
Cultures: Two cultures (CBS 121247 and AR 4286) differ significantly
in their morphology. CBS 121247: Colonies on PDA attaining 18
mm diam after 40 d at 23 °C, irregularly furrowed, shortly velvety,
dark brown and dark grey to almost black, with whitish submerged
mycelium at margin; margin diffuse, irregular; reverse dark brown,
almost black with orange-brown to whitish margins. Colonies on
MEA attaining 17 mm diam after 40 d at 23 °C, flat, glabrous with
scant aerial mycelium, black with dark brown margins; margin clear,
slightly wavy; black with dark brown margins. AR 4286: Colonies on
PDA attaining 33 mm diam after 40 d at 23 °C, radially furrowed,
velvety, whitish to greyish orange, with droplets of clear exudate;
margin well-defined, slightly wavy; reverse reddish orange to dark
brown; agar stained with orange pigment. Colonies on MEA attaining
15 mm diam after 40 d at 23 °C, slightly radially furrowed, greyish
orange overlaid by white short felty aerial mycelium; margin welldefined,
slightly wavy; reverse reddish orange. Sterile perithecia
observed in CBS 121247 incubated at 2/10 °C dark/light regime for
4.5 mo on MYA.
Habitat: On overwintered fallen or still hanging leaves of Corylus
californica (Betulaceae).
Distribution: Canada (British Columbia) and U.S.A. (WA).
Holotype: U.S.A., Washington, Mason Co., Potlatch State Park,
next to U.S. route 101, on overwintered fallen leaves, 16 May
2006, M.V. Sogonov MS0364b (BPI 877465C, ex-type culture CBS
121247).
Additional specimen examined: Canada, British Columbia, Vancouver Island,
Goldstream Provincial Park, on overwintered but still hanging leaves, 11 May 2006,
M.V.Sogonov MS0408 (BPI 877526A) GenBank EU254789; U.S.A., Washington,
Mason Co., Potlatch State Park, on overwintered fallen leaves, 16 May 2006, M.V.
Sogonov MS0363a culture AR 4286 (BPI 877466B).
Notes: Perithecia of Gnomonia orcispora have marginal necks and
are thus distinct from other species of Gnomonia on Corylus in
North America.
Gnomonia ostryae De Not., Sfer. Ital. cent. 1, fasc. 1: 42. 1863.
5. 8I–L; 6G–H; 8A–H.
≡ Apiognomonia ostryae (De Not.) M. Monod, Beih. Sydowia 9: 50 1983.
= Gnomonia veneta Speg., Michelia 1: 457. 1879.
Perithecia solitary, without stroma, hypophyllous, on leaf blade or
veins, in loose irregular groups, immersed at first, erumpent later,
black, oblate or suboblate when moist, 130–200 µm high × 170–260
µm diam, concave when dry. Necks eccentric to marginal, slightly
curved, 175–290 µm long, 25–45 µm wide at base, 25–45 µm
wide at apex. Asci fusiform, 49–57 × 12–16 µm, apical ring 2.9–3.8
µm diam, with eight ascospores arranged irregularly multiseriate
to obliquely uniseriate. Ascospores varying from fusiform with both
ends gradually tapering although rounded at tips to oblanceolate
or obovoid, broadened in upper part, with distal end extensively
rounded or smoothly truncated, inequilateral, (12.5–)15–17(–20.5)
× (3–)3.5–4.5(–6) µm (mean = 16 × 4, SD 1.5, 0.5, n=90), l:w
(3–)3.6–4.1(–4.9) (mean = 3.9, SD 0.4), two-celled, constricted at
www.studiesinmycology.org
25