Ophiocordyceps tortuosa Hong Yu bis, D.X. Tang & J. Zhao, 2023

Tang, Dexiang, Zhao, Jing, Lu, Yingling, Wang, Zhiqin, Sun, Tao, Liu, Zuoheng & Yu, Hong, 2023, Morphology, phylogeny and host specificity of two new Ophiocordyceps species belonging to the " zombie-ant fungi " clade (Ophiocordycipitaceae, Hypocreales), MycoKeys 99, pp. 269-296 : 269

Ophiocordyceps tortuosa Hong Yu bis, D.X. Tang & J. Zhao sp. nov.

Fig. 3

Etymology.

Tortuosa = tortuous, the epithet referred to the “tortuous” arrangement of ascospores in the asci.

Diagnosis.

The difference between Ophiocordyceps tortuosa and related species is that Ophiocordyceps tortuosa produces lanceolate and obvious separate ascospores, while O. contiispora produces fusiform and no obvious separate ascospores.

Holotype.

China, Yunnan Province, Puer City, Simao District. Infected Colobopsis sp. ( Formicinae ) biting into a leaf of Lauraceae Juss., 22°42'40"N, 100°57'28"E, alt. 1345 m, 03 October 2022, Hong Yu bis (YHH 2210035 - preserved in the Yunnan Herbal Herbarium).

Description.

Sexual morph: External mycelia produced from all orifices and sutures, often covering the host body, initially white turning brown. Stromata single to multiple, produced from dorsal pronotum, part branched, 16-24 mm in length, cylindrical, pale white to light brown, becoming pinkish at the apical part. Fertile region of lateral cushions, 1-3, commonly 2 per stroma, hemispherical, chocolate brown at maturity, 1-1.9 × 0.8-1.3 mm. Perithecia immersed to partially erumpent, flask-shaped, (211-) 218-298 (-305) × (94-) 99-142 (-158) μm, with short, exposed neck or ostiole. Asci 8-spored, hyaline, cylindrical, (92-) 96-132 (-134) × 7-11 (-13) μm. Ascus caps slightly prominent, hemispherical, 4-5 × (2-) 3-4 μm. Ascospores hyaline, thin-walled, lanceolate, tortuous arrangement in the ascus, 47-64 × 5-7 μm, 6-7-septate, gently curved at round apex, tapered end shorter than round apex.

Asexual morph: Hirsutella -A type associated with the apical part of stromata. Hirsutella -C type produced from the leg and antennal joints. Phialides lageniform, 54-99 μm long, 4-6 μm width at base, tapering to a long neck, 1-2 μm in width. Conidia fusiform to limoniform, 6-8 × 3-5 μm, slightly narrowing at the top.

Germination process: The released ascospores germinated within 48 h to produce 1-2 long and extremely narrow hair-like capilliconidiophores, (27-) 44-65 (-69) × 1-2 μm, bearing a single terminal capilliconidium, (5-) 6-9 × 3-4 (-5) μm, hyaline, smooth-walled, limoniform to fusiform, slightly narrowing and curved at the top.

Host: Colobopsis sp. ( Formicinae ).

Habitat.

Subtropical monsoon evergreen broad-leaved forest. Infected Colobopsis sp. biting into a leaf of Lauraceae Juss., from 1.2 to 2.4 m above the ground.

Distribution.

China, Yunnan Province, Puer City.

Material examined.

China, Yunnan, Puer City, Simao District . Infected Colobopsis sp. biting into a leaf of Lauraceae Juss., 22°42'40"N, 100°57'28"E, alt. 1,345 m, 03 October 2022, D.X. Tang (YHH 2210003, YHH 2210004, YHH 2210005, YHH 2210006) .

Notes.

In the phylogenetic tree, the new species O. tortuosa was sister to O. contiispora (Fig. 1 : BS = 100%, BPP = 100%) within O. unilateralis core clade (Fig. 1 : BS = 100%, BPP = 100%). Ophiocordyceps tortuosa was distinct from other species of the O. unilateralis core clade in that it produced lanceolate, obvious separate and tortuous arrangement ascospores in the ascus and produced branched stromata, slightly narrowing conidia (Table 3 ).

Figures

Figure 1. Phylogenetic tree of Ophiocordyceps and related genera, based on the concatenation of LSU, SSU, TEF 1 α, RPB 1 and RPB 2 sequence data. The tree was generated from an alignment of 4,827 sites and 143 taxa (38 within O. unilateralis). The phylogeny was inferred using the IQ-tree. Values at the nodes represent IQ-tree bootstrap proportions (on the left) and posterior probabilities (on the right). All values were shown at the nodes. The scale bar 0.02 indicates the number of expected mutations per site. The two new species were indicated in blue and red font within O. unilateralis core clade. Two species (T. inflatum OSC 71235 and T. ophioglossoides CBS 100239) in Tolypocladium were used as the outgroup taxa.

Figure 3. Ophiocordyceps tortuosa a-d infected Colobopsis sp. biting into a leaf of Lauraceae Juss e the three ascomata produced from the stroma f, g cross-section of ascomata showing the perithecial arrangement h, i asci j, k ascospores l, m ascospore with capilliconidiophores n capilliconidium o-q phialides r conidia. Scale bars: 4000 µm (a, b); 3000 µm (c, d); 2000 µm (e); 200 µm (f); 100 µm (g); 20 µm (h, i); 10 µm (j, k); 20 µm (l, m); 10 µm (n); 20 µm (o-r).