Ophiocordyceps fenggangensis X. C. Peng & T. C. Wen, 2024

Peng, Xing-Can, Wen, Ting-Chi, Wei, De-Ping, Liao, Yu-Hong, Wang, Yi, Zhang, Xian, Wang, Gui-Ying, Zhou, Yun, Tangtrakulwanich, Khanobporn & Liang, Jian-Dong, 2024, Two new species and one new combination of Ophiocordyceps (Hypocreales, Ophiocordycipitaceae) in Guizhou, MycoKeys 102, pp. 245-266 : 245

Ophiocordyceps fenggangensis X. C. Peng & T. C. Wen sp. nov.

Fig. 2

Etymology.

Named after the location where the type specimen was found, Fenggang County, Guizhou Province, China.

Diagnosis.

Parasitic on a larva of Lepidoptera . Stroma arising from the junction between head and thorax of lepidopteran larva, with a sterile tip. Perithecia immersed, grey-white.

Sexual morph.

Stroma solitary, unbranched, brown to grey-white, 102 × 1-1.5 mm. Fertile part up to 24 × 1.5 mm, cylindrical, attenuated toward the apex, grey-white when fresh, yellowish when dry, surface spinous due to the protruding ostioles, with a sterile tip (ca. 0.5 mm in length). Stipe cylindrical, brown to black, fibrous, 77.5 × 1-1.2 mm. Perithecia 306-496 × 134-223 μm (x̄= 388.4 × 175.9 µm, σ = 57.35 × 31.05, n = 15), immersed, ovoid to oblong-ovate. Asci 91-176 × 2-8 μm (x̄= 136.5 × 5.3 µm, σ = 38.22 × 2.63, n = 20), cylindrical, hyaline, with thickened apex. Apical cap 2.5-5.0 × 3.5-5.6 μm (x̄= 3.6 × 4.7 µm, σ = 0.78 × 0.48, n = 20), hyaline, hemispherical. Ascospores 0.3-0.7 µm (x̄= 0.4 µm, σ = 38.22 × 2.63, n = 20) wide, filiform, hyaline, easily breaking into part-spores. Secondary ascospores 2.8-6.0 × 0.3-0.7 μm (x̄= 4.0 × 0.4 µm, σ = 0.89 × 0.08, n = 20), cylindrical, smooth-walled. Asexual morph: undetermined.

Culture characteristics.

Colonies on PDA, attaining a diameter of 28-32 mm within 39 d at 20 °C, dense, leathery, cream white, convex, undulate margin, reverse brown, radial striation, no sporulation observed.

Material examined.

China, Guizhou Province, Fenggang County, Yongan Town (28°05′30.83″N, 107°31′53.38″E, alt. 1149 m), on dead larva of Lepidoptara, 28 April 2021, Xing-Can Peng, FG 21042850 (HKAS 125848 holotype, GACP FG21042850 ex-type living culture) .

Notes.

Multigene phylogenetic analysis showed that Ophiocordyceps fenggangensis forms a sister clade to O. musicaudata with a high support value (98% ML / 0.93 PP) and grouped with O. alboperitheciata and Hirsutella kuankuoshuiensis (Fig. 1 ). Ophiocordyceps fenggangensis GACP FG21042850 and O. musicaudata GACP SY22072879 have 8 bp differences of nucleotides (0 bp in LSU, 3 bp in tef1-α and 5 bp in rpb1). Morphologically, Ophiocordyceps fenggangensis is distinguished from O. musicaudata in having a solitary unbranched shorter stroma, longer perithecia, smaller asci, narrower ascospores and disarticulating ascospores. Ophiocordyceps alboperitheciata is distinct from O. fenggangensis by its superficial, white to nearly light brown fertile part and ovoid perithecia ( Fan et al. 2021), whereas our new species has grey-white to yellowish fertile part and immersed, ovoid to oblong-ovate perithecia. Additionally, the stroma of O. fenggangensis is longer than that of O. alboperitheciata . Perithecia and asci of O. fenggangensis are smaller than those of O. alboperitheciata . Hirsutella kuankuoshuiensis was described only from its asexual morph which is characterised by clavate, narrow fusiform or botuliform conidia; and subulate or slender columnar phialides tapering gradually to a long narrow neck ( Qu et al. 2021). BLAST search result showed that the ex-type strain (GACP FG21042850) matches Hirsutella kuankuoshuiensis GZUIFR-2012KKS3-1; however, they are different in 59 bp (including 1 gap) and 8 bp (including 1 gap) within ITS and rpb1 sequences, respectively. The detailed comparisons of the morphologies between these four aforementioned species are shown in Table 2 . Based on the morphological differences, we introduce this fungus as a new species of Ophiocordyceps .

Figures

Figure 1. Phylogram generated from Maximum Likelihood analysis, based on combined LSU, ITS, SSU, tef 1 - α, rpb 1 and rpb 2 sequence data. ML bootstrap values equal to or greater than 95 % and the PP equal to or greater than 0.90 are given above each node. The newly-generated sequences are indicated in blue. Type strain, type specimens or neotype are denoted in black bold.

Figure 2. Ophiocordyceps fenggangensis (holotype HKAS 125848) a habitat b host imbedded into the soil with the stroma emerging from the ground c stroma arising from the larva of Lepidoptera d host e, f reverse and front view of the culture on PDA g part of fertile head h part of fertile head with sterile tip (arrow indicate) i perithecia j-m asci n ascus cap o part of ascospores p secondary ascospores. Scale bars: 2 cm (c, e, f); 5 mm (d); 1 mm (g, h); 100 µm (i, j); 25 µm (k-m); 10 µm (n); 5 µm (o); 2 µm (p).