Parastagonospora zhaotongensis Y. Gao, H. Gui & K. D. Hyde, 2024

Gao, Ying, Zhong, Tingfang, Eungwanichayapant, Prapassorn Damrongkool, Jayawardena, Ruvishika S., Hyde, Kevin D., Faraj, Turki Kh., Wanasinghe, Dhanushka N. & Gui, Heng, 2024, Two new species of Parastagonospora and a new species of Phaeoseptoriella (Phaeosphaeriaceae, Pleosporales) from grasslands in Yunnan Province, China, MycoKeys 109, pp. 239-263 : 239-263

Parastagonospora zhaotongensis Y. Gao, H. Gui & K. D. Hyde sp. nov.

Fig. 3

Etymology.

The specific epithet “ zhaotongensis ” refers to Zhaotong City, where the holotype was collected.

Holotype.

HKAS 132983 .

Description.

Saprobic on decaying stem of Dactylis glomerata ( Poaceae ). Sexual morph: Undetermined. Asexual morph: Conidiomata 70–85 μm high × 80–110 μm diam (x – = 76 × 94 μm, n = 10) 80–110 μm diam × 70–85 μm high (x – = 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 (x – = 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 (x – = 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 (x – = 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 Dactylis glomerata ( Poaceae ), 27 August 2022, Ying Gao, QG 44 A ( HKAS 132983 , holotype), ex-type ( CGMCC 3.24519 ) • ibid. QG 44 B ( HKAS 132984 , paratype), ex-paratype ( CGMCC 3.24520 ) .

Note.

Based on multi-locus phylogenetic analyses, our strains of Parastagonospora zhaotongensis ( CGMCC 3.24519 and CGMCC 3.24520 ) are closely related to Para. uniseptata (MFLUCC 13-0387) and Para. poae . Parastagonospora uniseptata was reported on Daucus sp. from Italy by Li et al. (2015). Pairwise nucleotide comparison indicates that our strains differ from Parastagonospora uniseptata 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 tef 1 - α (2.21 %, without gaps). The rpb 2 sequence of Parastagonospora uniseptata was not available for comparisons. Morphologically, Parastagonospora zhaotongensis 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) (Table 4 ). The pairwise nucleotide comparison showed that our strains ( CGMCC 3.24519 and CGMCC 3.24520 ) differ from Parastagonospora poae ( 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 rpb 2 (4.00 %, without gaps). SSU and tef 1 - α data for Parastagonospora poae were not provided. Parastagonospora zhaotongensis 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) (Table 4 ).

Figures

Figure 3. Asexual morph of Parastagonospora zhaotongensis (HKAS 132983, holotype) on a dead stalk of Dactylis glomerata a, b conidiomata on the host c vertical section of conidioma d conidioma wall e conidiogenous cells arise from the wall and develop conidia f conidia g germinating conidium h cultures on PDA from above and reverse. Scale bars: 30 μm (c); 15 μm (d); 10 μm (e – g).