Fusarium brachypodum Zhi.Y. Zhang, Y.F. Han & Z.Q. Liang, 2023

Zhang, Zhi-Yuan, Li, Xin, Chen, Wan-Hao, Liang, Jian-Dong & Han, Yan-Feng, 2023, Culturable fungi from urban soils in China II, with the description of 18 novel species in Ascomycota (Dothideomycetes, Eurotiomycetes, Leotiomycetes and Sordariomycetes), MycoKeys 98, pp. 167-220 : 167

Fusarium brachypodum Zhi.Y. Zhang, Y.F. Han & Z.Q. Liang sp. nov.

Fig. 24

Etymology.

Refers to the sporodochial conidia connected by 1-3 short-stalks.

Type.

China: Guizhou Province, Guiyang City, Qianlingshan Park 26°59'03"N, 106°69'57"E, soil, 13 Sep 2019, Z.Y. Zhang (HMAS 351876 holotype designated here, ex-type living culture CGMCC 3.20776 = GZUIFR 21.910) .

Description.

Culture characteristics (14 d at 25 °C): Colony on PDA 79 mm diam., milk white (1A2), flat, velvety, with scant and short aerial mycelium, rounded, margins irregular; reverse white (1A1). Colony on MEA 63 mm diam., white (1A1), flat, cottony, rounded, margins regularly; reverse white (1A1). Colony on OA 58 mm diam., white (1A1), flat, surface khaki granular, rounded, margin entire; reverse white (1A1).

Hyphae abundant, branched, septate, hyaline, smooth, 1.0-4.0 μm diam. Conidiophores arising from aerial hyphae, straight or flexuous, hyaline, smooth-walled, unbranched or sparingly branched, bearing terminal or monophialides, often reduced to single phialides. Phialides subcylindrical to cylindrical, straight or flexuous, smooth, 12-22 μm long, 3.5-4.0 μm at the widest point. Aerial conidia forming small false heads on the tips of the phialides, hyaline, subcylindrical to cylindrical, straight or flexuous, smooth-walled, aseptate, 11.5-34.0 × 2.5-4.5 µm (av. 24.5 × 3.6 μm, n = 50). Sporodochia abundant. Conidiophores in sporodochia verticillately branched, consisting of a short, smooth-walled stipe, phialides cylindrical to lageniform, or irregular, 12.5-18.5 × 2.5-4.5 µm, bearing apical whorls of 2-3 monophialides or as single lateral monophialide. Sporodochial conidia smooth-walled, lunate to falcate, curved or somewhat straight, robust, with an elongated or whip-like curved apical cell and papillate to elongate, well-developed foot-shaped, sometimes poorly development basal cell, always aggregated, with connected by 1-3 short-stalked; 1-3 septate, sometimes aseptate, 1-septate conidia: 26.5-29 × 3.5-6.0 μm (av. 28.2 × 4.6 μm, n = 50), 2-septate conidia: 38.0-45.0 × 4.5-6.0 μm (av. 41.7 × 5.5 μm, n = 50), 3-septate conidia: 32.5-61.0 × 4.0-6.0 μm (av. 46.0 × 4.3 μm, n = 50), aseptate conidia: 24.5-45.0 × 3.5-6.0 μm (av. 34.7 × 4.0 μm, n = 50). Chlamydospores rare, subglobose to globose, hyaline, smooth-walled, intercalary, solitary, 9.0-13.5 μm (av. 11.8 μm, n = 5) diam. Coiled sometimes from the substrate and aerial mycelium. Microconidia not observed. Sexual morph unknown.

Additional specimens examined.

China: Jiangxi Province, Jian City, Jinggangshan University 27°11'30"N, 115°03'19"E, soil, 22 Aug 2019, Z.Y. Zhang, GZUIFR 21.911 .

Notes.

Fusarium brachypodum was introduced as a new species while adding one more species to the Fusarium buharicum species complex (FBSC; Geiser et al. 2013; O’Donnell et al. 2013). Our isolates formed a single clade nested in FBSC (Fig. 23 ), which comprise F. abutilonis , F. buharicum , F. convolutans , F. guadeloupense and F. sublunatum . However, Fusarium brachypodum differs from members of FBSC in its presence of hyphae coiled, chlamydospores, absent microconidia and sporodochial conidia connected by 1-3 short stalks ( Gerlach and Nirenberg 1982; Sandoval-Denis et al. 2018b).

Figures

Figure 23. Concatenated phylogeny of the ITS, LSU, RPB 2 and EF 1 A gene regions of species in Fusarium. Sixty-three strains are used. The tree is rooted in Ilyonectria destructans (CBS 264.65) and I. capensis (CBS 132815). The tree topology of the BI was similar to the ML analysis. Bayesian posterior probability (≥ 0.7) and ML bootstrap values (≥ 70 %) are indicated along branches (PP / ML). Novel species are in blue and bold font and " T " indicates type derived sequences.

Figure 24. Fusarium brachypodum (from ex-holotype CGMCC 3.20776) a-c upper and reverse views of cultures on PDA, MEA and OA 14 d after inoculation d, e conidiophores and phialides on aerial mycelium f-i sporodochia, sporodochial conidiophores and conidia j spiral hyphae k chlamydospores l conidia. Scale bars: 10 µm (d-l).