Phyllosticta abieticola
Phyllosticta abieticola Wikee & Crous, Stud in Mycol 76: 11. 2013
Index Fungorum: IF805654; Facesoffungi: FoFxxxxx; MycoBank: MB805654.
Pathogenic on living leaf of Abies concolor. Sexual morph: Ascostromata solitary, black, erumpent, globose. Asci 65–120 × 12–15 μm, bitunicate, hyaline, clavate to broadly fusoid-ellipsoid, with visible apical chamber, 2 μm diam. Ascospores (15–)16–18(–20) × (6–)7 μm, bi-to multiseriate, hyaline, smooth, granular to guttulate, aseptate, straight, rarely curved, widest in the middle, limoniform with obtuse ends. Asexual morph: Conidiomata (on PNA) up to 250 μm diam., pycnidial, solitary, black, erumpent, globose, exuding colourless conidial masses, elongated in culture on PNA. Peridium up to 30 μm thick, composed of several layers of textura angularis, inner wall of hyaline textura angularis. Ostiole up to 15 μm diam., central. Conidiophores 10–25 × 4–6 μm, subcylindrical to ampulliform, reduced to conidiogenous cells, or with 1 supporting cell, that can be branched at the base. Conidiogenous cells 7–15 × 3–5 μm, terminal, subcylindrical, hyaline, smooth, coated in a mucoid layer, proliferating several times percurrently near apex. Conidia (11–)13–16(–18) × (7–)8 μm, solitary, hyaline, aseptate, thin and smooth-walled, granular, or with a single large central guttule, fusoid-ellipsoid, tapering towards a narrow truncate base, 2–3 μm diam., enclosed in a thin persistent mucoid sheath, 3–4 μm thick, and bearing a hyaline, apical mucoid appendage, (15–)20–25(–30) × 1.5(–2) μm, flexible, unbranched, tapering towards an acutely rounded tip.
Culture characteristics: Colonies erumpent, spreading with moderate aerial mycelium, covering dish after 1 month at 25 ºC. On OA surface iron-grey. On PDA and MEA surface grey-olivaceous, reverse iron-grey.
Representative isolate: Canada, on living leaf of Abies concolor, Jan. 2001, M. Forve, holotype CBS H-21389, CBS 112067 (ex-type culture).
Host: Abies concolor (Bissett & Palm 1989).
Known distribution: Canada (Bissett & Palm 1989).
GenBank Numbers: ITS - KF170306, LSU - EU754193, ACT - KF289238.
Notes: Phyllosticta abieticola was originally identified as P. abietis, which is distinguished by having smaller conidia (7–12 × 6.5–9 μm), and a sheath up to 1.5 μm wide, with apical appendages up to 2.5 μm long when present (Bissett & Palm 1989).
References:
Bissett J, Palm ME (1989) Species of Phyllosticta on conifers. Canadian Journal of Botany 67: 2278–2285.