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

Fig. 4

Etymology.

The epithet refers to the collecting site from the Yunjushan Mountain in China.

Holotype.

HFJAU10005

Description.

Saprobic on decaying bamboo culms submerged in freshwater habitats. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, olivaceous or dark brown, hairy, velvety. Mycelium mostly immersed, consisting of branched, septate, smooth, subhyaline to pale brown hyphae. Conidiophores 100-175 μm × 5.5-10 μm (x- = 129 × 7.1 μm, n = 30), single or in groups of 2 or 3, macronematous, mononematous, erect, straight or slightly flexuous, 4-7-septate, unbranched, olivaceous to dark brown, smooth, cylindrical, rounded at the apex. Conidiogenous cells monoblastic, integrated, terminal, determinate, pale to dark brown, cylindrical. Conidia 39-67.5(-77) μm × (7-)9.5-13.5(-16.5) μm (x- = 52 × 12 μm, n = 30), acrogenous, solitary, obpyriform or obclavate, thick-walled, tapering towards the rounded apex, slightly curved, truncate at the base, 7-13-distoseptate, guttulate, smooth-walled, olivaceous, dark brown when mature, sometimes with the percurrent proliferation which forms another conidium from the conidial apex.

Cultural characteristics.

Conidia germinating on PDA within 24 h and germ tubes produced from both ends. Colonies on PDA reaching 12-18 mm diam. at 14 days at 25 °C, in natural light, with fluffy, dense, thin olivaceous mycelium in the centre, becoming sparse and paler at the entire margin; reverse dark brown, pale brown at the smooth margin.

Material examined.

China, Jiangxi Province, Jiujiang City, Yongxiu County, Yunjushan Mountain , alt. 672.5 m, 29.23°N, 115.59°E, on decaying bamboo culms submerged in a freshwater stream, 28 Apr 2020, Z. J. Zhai and W. W. Li, YJS-42 ( HFJAU 10005, holotype), ex-type living culture, JAUCC 4723 = JAUCC 4724 .

Notes.

In the phylogenetic analysis, D. yunjushanensis clusters with D. obclavata and D. rayongensis with moderate support (BS/PP = 81/1.00). However, D. yunjushanensis is easily distinguished from D. obclavata by its comparatively wider (5.5-10 μm vs. 5-7 μm) conidiophores and conidia ((7-)9.5-13.5(-16.5) μm vs. 9-11 μm) ( Luo et al. 2019). Moreover, the percurrent proliferation of conidia was not observed in D. obclavata ( Luo et al. 2019). Distoseptispora yunjushanensis has shorter conidia (39-67.5(-77) μm vs. (36-)60-106(-120) μm) and wider conidiophores (5.5-10 μm vs. 3.5-5.5 μm) than those of D. rayongensis ( Hyde et al. 2020). The morphology of D. yunjushanensis is similar to D. guttulata and D. songkhlaensis in having the obclavate conidia, but differs in having wider (5.5-10 μm vs. 3.5-5.5 μm and 4-5.5 μm) conidiophores, shorter (39-67.5(-77) μm vs. 75-130(-165) μm and 44-125 μm) and proliferating conidia ( Yang et al. 2018; Dong et al. 2021). Additionally, D. yunjushanensis can be distinguished from D. guttulata by its distoseptate conidia ( Yang et al. 2018).

Figures

Figure 4. Distoseptispora yunjushanensis (HFJAU 10005, holotype) a, b colonies on bamboo culms c-f conidiophores with conidia g-i young conidia j-l mature conidia m conidium with proliferation n germinating conidium o, p culture on PDA from above and reverse. Scale bars: 100 µm (a, b), 20 µm (c-f, m, n), 5 µm (g-l).