Microdochium chuxiongense H. Yu, W. Q. Zou & D. X. Tang 2022, sp. nov.
Creators: name: Tang, De-Xiang
name: Zou, Wei-Qiu
name: Wang, Yao-Ming
name: Huang, Ou
name: Yu, Hong
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Sordariomycetes
Amphisphaeriales
Amphisphaeriaceae
Microdochium
Microdochium chuxiongense

description: Microdochium chuxiongense H. Yu, W.Q. Zou & D.X. Tang, sp. nov. (Figure 2)
MycoBank:— MB 844086
Etymology:— Referring to Chuxiong City where was this species collected.
Typus:— The Zixi Mountains, Chuxiong City, Yunnan Province, China (25°04′19.88′′ N, 110°54′60.46′′ E, alt. 2300 m), on pileus of Bondarzewia sp., 22 September 2020, Hong Yu (YHH 20400, holotype; YFCC 8794, ex-holotype living culture).
Asexual morph:— Mycelium immersed and superficial, hyphae hyaline, branched, smooth, septate, 2–3 μm wide (x̅=3 µm, n =30). Conidiophores cylindrical, straight, septate, 8–15 × 2–3 μm (x̅=11 × 2 µm, n =10), and borned from the hyphae. Conidiogenous cells sparse, solitary, clavate, occasionally curved or swollen, hyaline, smooth, septate, 27–74 × 2–3 μm (x̅=50 × 2 µm, n =20). Conidia single or multiple, long oval, shuttle or sickle, straight or curved, 0(–3)-septate, 4–12 × 2–5 μm (x̅=7 × 3 µm, n =30). Chlamydospores were produced directly from mycelium, single, round or palmate, 9–11 × 10 μm (x̅=10 × 10 µm, n =10). Sexual morph were not found.
Culture characteristics:— The colony was on PDA medium fast-growing, 55–60 mm (x̅= 58 mm, n =3) in diameter after 7 days. The center has obvious milky white aerial mycelium bulge, and the edge mycelium was smooth, back light yellow. The colony was 78–82 mm (x̅= 80 mm, n =3) in diameter after 14 days, with pale aerial mycelium cottony, forming an obvious black circle in centre, back dark brown.
Know distribution:— The Zixi Mountains, Chuxiong City, Yunnan Province, China.
Notes:— This study reported that M. chuxiongense was isolated from pileus of Bondarzewia sp., and was different from the host reported by previous studies. Phylogenetic analysis based on four genes showed that M. chuxiongense was formed a separate clade with M. indocalami and M. maculosum, it was a sister with M. indocalami, with strongly being supported by BI posterior probabilities (PP = 83%) and ML boostrap proportions (BP = 82%). The sequence length was 3255 bp for M. indocalami and M. chuxiongense, the gap sites of M. indocalami was 293 bp, and M. chuxiongense was 759 bp, their conserved sites were 2385 bp, and variable sites were 106 bp, 73% similar to M. indocalami and M. chuxiongense.
M. chuxiongense was very similar to M. indocalami in the colony, conidiophores and conidiogenous cells and conidia. However, it differed in the colony forming an obvious black circle in centre (Huang et al. 2020) (Table 2). Moreover, the shape of conidiophores differs from M. chuxiongense and M. indocalami. M. chuxiongense was cylindrical, straight, septate, 8–15 × 2–3 μm, M. indocalami was straight or slightly curved, septate, aggregated in the aerial mycelium (Table 2). In addition, the size and shape of conidiogenous cells also differ from two species, conidiogenous cells of M. indocalami was terminal or intercalary, denticulate, straight or bent, 11–28 × 2–3 μm. Nevertheless, M. chuxiongense was sparse, occasionally curved or swollen, 27–74 × 2–3 μm (Table 2). The size, shape and septate of conidia reported for M. indocalami (13–16 × 4–6 μm, cylindrical, clavate to obovoid, base usually flattened, 1–3-septate) were different from M. chuxiongense (4–12 × 2–5 μm, single or multiple, long oval, shuttle or sickle, straight or curved, 0–3-septate) (Table 2). Importantly, chlamydospores were observed in M. chuxiongense, and yet M. indocalami was not observed.
description: Published as part of Tang, De-Xiang, Zou, Wei-Qiu, Wang, Yao-Ming, Huang, Ou & Yu, Hong, 2022, Morphology and phylogeny of Microdochium chuxiongense sp. nov., a fungus from Southwest China, pp. 147-158 in Phytotaxa 555 (2) on page 151, DOI: 10.11646/phytotaxa.555.2.3, http://zenodo.org/record/6875964