Chaetosphaeriales » Chaetosphaeriaceae » Dinemasporium

Dinemasporium pseudodecipiens

Dinemasporium pseudodecipiens A. Hashim. & Kaz. Tanaka, in Hashimoto, Sato, Matsuda, Hirayama, Hatakeyama, Harada, Shirouzu & Tanaka, Mycoscience 56: 95 (2014)



Saprobic on dead stems or branches of Colutea arborescens and Fraxinus ornus. Sexual morph: undetermined. Asexual morph: Conidiomata 200–400 µm diam., 100–300 µm high, brown to black, superficial, solitary to gregarious, occasionally confluent, pulvinate, oval to rounded in outline, cupulate, with incurved margins, unilocular, setose. Conidiomatal setae composed of two types; a) 150400 × 214 μm, dark brown to black, conspicuous, subulate, unbranched, septate, tapered towards the apex, rigid, thick- and smooth-walled, arising from basal stroma; b) 50100 × 1.54 μm, pale brown to brown, inconspicuous, subcylindrical, with obtuse and paler apex, unbranched, smooth-walled, arising from lateral excipulum, occasionally from outer layers of the stroma. Conidiomatal wall composed of basal stroma 20–70 µm thick, of textura intricata with cells brown to pale brown, thick-walled, and well developed excipulum 10–30 µm thick, of textura porrecta with hyaline to pale brown, thick-walled cells. Conidiophores arising in the cavity of the conidiomata in a closely packed palisade, hyaline, subcylindrical, irregularly branched. Conidiogenous cells 10–20 × 2–4 µm, hyaline, discrete, subcylindrical with moderate periclinal thickenings in the collarette zone, thick-walled, smooth. Conidia 5–12 × 2–5 µm ( = 8 × 3 µm; n = 50), hyaline, naviculate to subellipsoidal, narrowed and rounded at both ends, thick-walled, smooth, bearing 2–7 µm long, unbranched, excentric appendage at each end.


Material examined: Italy, Province of Forlì-Cesena, Predappio, San Martino, on dead aerial branches of Colutea arborescens (Fabaceae), 29 October 2015, Erio Camporesi, IT2679 (MFLU 15-3635), (KUN, HKAS 93646); ibid., Trivella di Predappio, on dead aerial branches of Fraxinus ornus (Oleaceae), 26 February 2014, Erio Camporesi, IT1743 (MFLU 19-2865).


Notes: Two fresh collections (MFLU 15-3635/IT2679), MFLU 19-2865/IT1743) show similar morphology of conidomata, conidiogenous cells and conidia with D. pseudodecipiens. However, MFLU 15-3635/IT2679 has two types of conidiomatal setae (dark brown, erect, acuminate setae and pale brown, flexuous setae) which differ from MFLU 19-2865/IT1743 and MAFF 244352 which are black, subulate. Moreover, MFLU 15-3635/IT2679 has slightly larger conidia than MFLU 19-2865 (IT1743) and MAFF 244352. Phylogenetically, these two collections clustered with D. pseudodecipiens (MAFF 244351, MAFF 244352) Therefore, these two collections are identified as D. pseudodecipiens, and the differences noted above may reflect intra-species variation. We conclude that D. pseudodecipiens is a complex species, and that conidiomatal setae and conidia dimensions cannot be used to distinguish Dinemasporium species.



Dinemasporium pseudodecipiens (MFLU 15-3635) a Herbarium specimen b, c Appearance of black conidiomata on the host d Vertical section of conidiomata e Excipular elements and seta f Tissue details of basal stroma and excipulum g Superficial cells of conidioma h Conidiomatal seta i–l Discrete conidiogenous cells and developing conidia m-q Conidia. Scale bars d = 100 µm, e–h= 20 µm, i–l= 10 µm, m–q =5 µm.