Cordyceps qingchengensis L.S. Zha & T.C. Wen, 2019

Zha, Ling-Sheng, Wen, Ting-Chi, Huang, Shi-Ke, Boonmee, Saranyaphat & Eungwanichayapant, Prapassorn D., 2019, Taxonomy and biology of Cordyceps qingchengensis sp. nov. and its allies, Phytotaxa 416 (1), pp. 14-24 : 18

Cordyceps qingchengensis L.S. Zha & T.C. Wen sp. nov. ( Figs 3 , 4 )

Index Fungorum number IF556460; Facesoffungi number FoF 03405 .

Etymology:—the new species is named after Qingchengshan Mountain, its type locality.

Holotype:— MFLU 17-1022 (isotype: GACP 16070401 ).

Description:—Sexual morph: Stromata arising from head of cocooned pupa of a large silk moth, fleshy, yellow (fresh specimen), branched, total length 25 mm; single at base, then branched into several (often 3) forks, basal stipe and upper branches slightly cylindrical, moderate width, covered by light yellow mycelia, apices of branches obtuse. Fertile part located at the terminal part of every branch, 7–9 × 2.0– 2.5 mm, slightly wider than basal stipe and upper branches. Perithecia partially immersed at right angle to surface of fruiting body, ovoid but apex sharply pointed, 335–490 × 145–240 μm. Asci cylindrical, 180–200 (x =188, n=10) long and 2.4–4.0 (x =3.15, n=30) μm wide, caps hemispheric, 1.8–2.2 (x =2.0, n=30) μm high and 2.5–3.2 (x =2.85, n=30) μm wide, 8-spored. Ascospores filiform, 180–220 μm long and 0.45–0.65 (x =0.53, n=30) μm wide, not at all bifusiform and not broken into part-spores. Asexual morph: Unknown.

Material examined: — CHINA. Sichuan Province: Chengdu, Qingchengshan Mountain , 30°55′30′′N, 103°29′44′′E, about 1000 m altitude, 4 July 2016, Ling-Sheng Zha ( MFLU 17-1022 , holotype; GACP 16070401 , isotype) .

Distribution: — China (Sichuan).

Host: —Growing on the ovate cocooned pupa of a large silk moth ( Lepidoptera : Bombycidae ) in humid soil of a broad-leaved forest. The cocoon is ovate and thick, 21 × 8 mm.

Notes: —Morphologically, Cordyceps qingchengensis (sexual morph) is similar to C. bifusispora O.E. Erikss. and C. tenuipes (= C. takaomontana ), but can easily be identified by its unique host (ovate cocooned pupa of a large silk moth) and branched stroma. Morphological differences of Cordyceps qingchengensis and its allies are outlined in Table 2.

ITS sequence of Cordyceps qingchengensis is most similar (only 0.9 % bp difference across 569 bp) to that of C. cicadae (Miq.) Massee (Chanhua, RCEF HP090724-31 and our collections, Zha et al. 2018), but their TEF1-α sequence are sufficiently different (3.1% bp difference across 911 bp). Morphologically, C. cicadae (Miq.) Massee has large and irregularly branched stromata, broad ascospores and grows on cicada nymphs, features that are significantly different from C. qingchengensis ( Table 2). TEF1-α sequence of C. qingchengensis is most similar (1.7 % difference across 866 bp) to that of C. bifusispora (EFCC 8260, spat 08-129 and spat 08-133.1). Unfortunately, there is no ITS sequence for C. bifusispora . The phylogenetic analyses also support C. qingchengensis as a new taxon despite being closely related to C. bifusispora , C. cicadae (Miq.) Massee and C. tenuipes ( Figs 1 , 5 ).

Biology: —The cocoon of the host is a little rotted ( Fig. 3b ) and the pupa in the cocoon had been seriously degraded by the fungus. We infer the life cycle of the fungus should be as follows.

In the previous summer, an old silk moth larva prepared for pupation in the soil when there was heavy rain, and due to extremely humid soil environment, the insect was infected by the fungus. Several days later a pupa had formed in its thick silk cocoon and the insect was killed by the fungus in the cocoon, and as a result a sclerotium (ossified insect) came into being. Due to either dry soil environment or low temperatures in the next year, the sclerotium did not germinate, but with the advent of the rainy season in the next summer, the sclerotium began to germinate and fruiting body of the fungus formed at last.

Figures

FIGURE 1. ML tree of Cordyceps qingchengensis sp. nov. and its allies inferred from a combined SSU, LSU and TEF1-α dataset. Bootstrap support values greater than 70% are indicated above the nodes.

FIGURE 3. Cordyceps qingchengensis (MFLU 17–1022, holotype). a-b. Growing in the wild and dug out. c. Habitat environment.

FIGURE 4. Cordyceps qingchengensis (MFLU 17–1022, holotype). a. Fertile head of dry fruiting body. b. Surface of fertile head. c. Perithecia in profile. d–e. Asci. f–h. Ascospores. Scale bars: a = 1 mm, b = 200 µm, c = 100 µm, d–e = 20 µm, f-h = 10 µm.

FIGURE 5. NJ tree of Cordyceps qingchengensis and its allies inferred from ITS gene data. Bootstrap values greater than 75% are indicated above the nodes.