Parastagonospora zhaotongensis Y. Gao, H. Gui & K.D. Hyde, in Gao, Zhong, Eungwanichayapant, Jayawardena, Hyde, Faraj, Wanasinghe & Gui, MycoKeys 109: 250 (2024)
Index Fungorum number: IF 902469; MycoBank number: MB 902469; Facesoffungi Number: FoF16259
Saprobic on decaying stem of Dactylisglomerata (Poaceae). Sexual morph: Undetermined. Asexual morph: Conidiomata 70–85 μm high × 80–110 μm diam (x̅ = 76 × 94 μm, n = 10) 80–110 μm diam × 70–85 μm high (x̅ = 94 × 76 μm, n = 10), flattened, solitary, immersed in the epidermis of the host, globose to subglobose, brown to dark brown spots. Conidiomatal wall 5–13 µm wide (x̅ = 8 μm, n = 30), thin wall, 2–3 layered, composed of pale brown cells of textura angularis, with inner layer comprising hyaline cells. Conidiogenous cells (3.5–)4.5–6(–6.5) × (3–)4–5.5(–6) μm (x̅ = 5.5 ± 0.74 × 5 ± 0.77 μm, n = 20), hyaline, globose to subglobose, smooth-walled. Conidia (22–)25–30(–32)× (2.7–)3–3.4(–3.7) μm (x̅ = 28 ± 2.45 × 3.3 ± 0.21 μm, n = 35), hyaline, 0–3-septate, cylindrical to subcylindrical, smooth-walled, rounded at apex, slightly truncate at base, guttulate.
Culture characteristics – Colonies on PDA, reaching 20–25 mm diam., after three weeks at 25–27 °C, with circular, floccose, white from the above and, in reverse pale yellow.
Material examined – China, Yunnan Province, Qujing City (26°37’38″N, 103°15’29″E), on decaying stem of Dactylisglomerata (Poaceae), 27 August 2022, Ying Gao, QG44A (HKAS 132983, holotype), ex-type (CGMCC 3.24519) • ibid. QG44B (HKAS 132984, paratype), ex-paratype (CGMCC 3.24520).
Notes – Based on multi-locus phylogenetic analyses, our strains of Parastagonosporazhaotongensis (CGMCC 3.24519 and CGMCC 3.24520) are closely related to Para.uniseptata (MFLUCC 13-0387) and Para.poae. Parastagonosporauniseptata was reported on Daucus sp. from Italy by Li et al. (2015). Pairwise nucleotide comparison indicates that our strains differ from Parastagonosporauniseptata in 17/573 bp of ITS (2.97%, with 4 gaps), 2/834 bp of LSU (0.24%, without gaps) and 20/906 bp of tef1-α (2.21%, without gaps). The rpb2 sequence of Parastagonosporauniseptata was not available for comparisons. Morphologically, Parastagonosporazhaotongensis is distinguished by its conidiogenous cells (globose to subglobose vs. ampulliform to broadly conical, phialidic), and conidia (22–32 μm long, 0–3-septate vs. 14–18 μm long, 1-septate). The pairwise nucleotide comparison showed that our strains (CGMCC 3.24519 and CGMCC 3.24520) differ from Parastagonosporapoae (CBS 135089) in 15/562 bp of ITS (2.67%, with 4 gaps), 2/828 bp of LSU (0.24%, without gaps), and 10/250 bp of rpb2 (4.00%, without gaps). SSU and tef1-α data for Parastagonosporapoae were not provided. Parastagonosporazhaotongensis differs from Para.poae in conidiomata (80–110 μm in diam., brown to dark brown spots vs. up to 250 μm in diam. black), conidiogenous cells (3.5–6.5 μm long, globose to subglobose vs. 6–10 μm long, ampulliform to subcylindrical) and conidia (2.7–3.7 μm wide, 0–3-septate vs. 2–2.5 μm wide, 1-septate).
Figure 1 – Asexual morph of Phaeoseptoriellapoaceicola (HKAS 128741, holotype) on a dead stalk of Dactylisglomerataa, b conidiomata on the host c, d vertical section of conidiomata e conidioma wall i conidiogenous cell arise from the wall and develop conidium f–h, j conidia k germinating conidium l cultures on PDA from above m cultures on PDA from the reverse. Scale bars: 30 μm (c); 20 μm (d, e, k); 10 μm (f–h, j); 5 μm (i).