Highlights of the Didymellaceae - Studies in Mycology

AveSkAMp et al.
Fig. 15. Phoma longicolla (CBS 124514). A–C. Fourteen-day-old colonies on OA (A), MEA (B) and CHA (C). D–F. Pycnidia. G. Section of the pycnidial wall. H. Conidia. Scale
bars: E–G = 100 μm; H = 50 μm; I–J = 10 μm.
broadly globose to irregular conidiomata with many white hyphal
outgrows and with a clear elongated neck around the ostioles, giving
it a irregular shape, measuring (170–)200–270(–285) × (115–)125–
205(–220) μm. Ostioles 1–3(–4), on a long elongated neck (up to 200
μm long). Often these pycnidia merge to an irregular mass of confluent
conidiomata. Pycnidial wall pseudoparenchymatous, composed of
isodiametric cells, 5–7 layers, 17–22 μm thick. Conidiogenous cells
phialidic, hyaline, simple, smooth, flask-shaped, ca. 4–5 × 3–5 μm.
Conidia broadly ellipsoidal to ovoid, thin-walled, smooth, hyaline,
aseptate 6–8.5(–10) × (3.5–)4–5(–5.5) μm, with (2–)3–9(–12) polar
guttules. Conidial matrix crème-white.
Culture characteristics: Colonies on OA 50–55 mm diam. after 7 d,
margin regular. Immersed mycelium hyaline with abundant pycnidia,
in some sectors covered by a low mat of felty to floccose mouse
50
grey aerial mycelium, with tufts of white mycelium near the colonies
margin. In the sectors with aerial mycelium, pycnidia are only
sparsely present; reverse hyaline, but leaden black and olivaceous
grey where the aerial mycelium is present. Colony on MEA 50–55
mm diam. after 7 d, margin regular. Immersed mycelium completely
covered by a floccose crème mat of white aerial mycelium; reverse
greenish olivaceous to olivaceous-black. Colony on CHA 55–60
mm diam. after 7 d, margin regular. Immersed mycelium brown
vinaceous to black. Aerial mycelium is occurring in sectors, felty,
pale grey to white; reverse black with incidentally a pale purplish
grey zone. Application of NaOH did not have any effect.
Specimens examined: Spain, Canary Isles, from Opuntia sp., 1980, J. de Gruyter,
holotype designated here CBS H-20238, ex-holotype culture CBS 124514 = PD
80/1189; Canary Isles, Gran Canaria, from Opuntia sp., June 1982, H.A. van der
Aa, CBS 347.82.