Distoseptispora yongxiuensis Z. J. Zhai & D. M. Hu, 2022

Zhai, Zhi-Jun, Yan, Jun-Qing, Li, Wei-Wu, Gao, Yang, Hu, Hai-Jing, Zhou, Jian-Ping, Song, Hai-Yan & Hu, Dian-Ming, 2022, Three novel species of Distoseptispora (Distoseptisporaceae) isolated from bamboo in Jiangxi Province, China, MycoKeys 88, pp. 35-54 : 35

Distoseptispora yongxiuensis Z. J. Zhai & D. M. Hu sp. nov.

Fig. 3

Etymology.

With reference to Yongxiu, from where the holotype was collected.

Holotype.

HFJAU10007

Description.

Saprobic on decaying bamboo culms. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, brown, hairy, glistening, often inconspicuous. Mycelium partly superficial, partly immersed in the substratum, composed of hyaline to pale brown, septate, branched hyphae. Conidiophores 112-253 × 4-9 μm (x- = 198 × 6.9 μm, n = 15), macronematous, mononematous, solitary or aggregated at the base, cylindrical, straight or slightly flexuous, 8-13-septate, olivaceous to dark brown, sharply curving near the base, paler at the apical part, rounded at the apex. Conidiogenous cells integrated, terminal, monoblastic, rarely polyblastic, cylindrical, olivaceous to dark brown. Conidia 46-74(-86) × 10-13(-16) μm (x- = 65.6 × 12.6 μm, n = 30), acrogenous, solitary, obclavate or obspathulate, straight or flexuous, rostrate, 6-9-euseptate, olivaceous to yellowish-brown or brown, becoming paler or hyaline towards the apex, guttulate, 2.5-4 μm wide at the base and 2.5-5 μm wide at the apex, with a darkened scar at the base.

Cultural characteristics.

Conidia germinating on PDA within 24 h and germ tubes produced from both ends. Colonies on PDA reaching 24-32 mm diam. at two weeks at 25 °C, in natural light, circular, with dense, light olivaceous mycelium on the surface with entire margin; reverse dark brown to black.

Material examined.

China, Jiangxi Province, Jiujiang City , Yongxiu County, alt. 680.5 m, 29.09°N, 115.62°E, on decaying bamboo culms submerged in a freshwater stream, 28 Apr 2020, Z. J. Zhai and W. W. Li, YJS-70 ( HFJAU 10007, holotype), ex-type living culture, JAUCC 4725 = JAUCC 4726 .

Notes.

In the multi-gene phylogenetic tree (Fig. 1 ), D. yongxiuensis clusters with D. suoluoensis . Nonetheless, D. yongxiuensis can be distinguished from D. suoluoensis by its shorter conidia (46-74(-86) μm vs. (65-)80-125(-145) μm) and polyblastic conidiogenous cells ( Yang et al. 2018). Additionally, D. suoluoensis has the percurrent proliferation of conidia, while it was not observed in D. yongxiuensis . Distoseptispora yongxiuensis is similar with D. bambusae ( Sun et al. 2020), D. palmarum ( Hyde et al. 2019) and D. meilingensis for the polyblastic conidiogenous cells, but D. yongxiuensis has wider conidia than those of D. bambusae (10-13(-16) μm vs. 5.5-9.5 μm) ( Sun et al. 2020), shorter conidia than those of D. palmarum (46-74(-86) μm vs. 35-180 μm) ( Hyde et al. 2019) and paler (yellowish-brown or brown vs. bright brown) conidia than those of D. meilingensis .

Figures

Figure 1. Phylogenetic tree of Distoseptispora, inferred from the combined regions (ITS-LSU-SSU- Tef 1 α) using Bayesian Inference (BI) analysis. The Aquapteridospora clade was used as the outgroup. The lineages with new species were shown in bold. PP ≥ 0.95 and BS ≥ 75 % were indicated around the branches. The new sequences generated in this study are given in bold.

Figure 3. Distoseptispora yongxiuensis HFJAU 10007, holotype) a Colonies on bamboo culm b, d conidiophores with conidia c conidiogenous cell bearing conidium e conidiogenous cells with young conidia f-k conidia l germinating conidium m culture on PDA from above and reverse. Scale bars: 100 µm (a), 20 µm (b-e, l), 5 µm (f-k).