Trichobotrys meilingensis G. P. Xu & Z. J. Zhai, 2024

Zhang, Wen-Jing, Xu, Gui-Ping, Liu, Yu, Gao, Yang, Song, Hai-Yan, Hu, Hai-Jing, Zhou, Jian-Ping, Chen, Ming-Hui, Fan, Deng-Mei, Hu, Dian-Ming & Zhai, Zhi-Jun, 2024, Multi-gene phylogenetic analyses revealed two novel species and one new record of Trichobotrys (Pleosporales, Dictyosporiaceae) from China, MycoKeys 106, pp. 117-132 : 117-132

Trichobotrys meilingensis G. P. Xu & Z. J. Zhai sp. nov.

Fig. 2

Etymology.

Referring to the collection site of the Meiling Mountain in Jiangxi Province, China.

Holotype.

HFJAU 10042 .

Description.

Saprobic on the stems of bamboo in freshwater habitats. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, white to yellow, hairy. Mycelium partly superficial, partly immersed, gregarious and creeping, composed of septate, branched, pale brown hyphae. Conidiophores 2.5–4.5 μm wide (x ̄ = 3.5 μm, n = 20), up to 510 μm long, mononematous, variously curved, dichotomously branched in the conidiophore, septate, thick-walled, verruculose, echinulate, brown to dark brown. Conidiophore branches 15–39 × 3–4 μm (x ̄ = 24.5 × 3.4 μm, n = 15), fertile, 0‒1 (‒ 2) - septate, verruculose, pale to dark brown. Conidiogenous cells 7–12 × 3–5 μm (x ̄ = 9.0 × 4.0 μm, n = 10), polyblastic, integrated, erect or curved, widely distributed in the fertile branches, denticulate, hyaline to brown. Conidia 7‒13 μm diam (x ̄ = 9.8 μm, n = 30), catenate, usually in branched, acropetal chains, aseptate, globose, verruculose, echinulate, sometimes guttulate, yellow brown to dark brown.

Cultural characteristics.

Conidia germinating on PDA within 24 h. Colonies incubated on PDA media at 25 ° C attaining 30.5 mm diam after 9 days, in natural light, circular, white, slightly cottony, yellow at the margin part, with white dense aerial mycelium; reverse yellow, white at the entire margin.

Material examined.

China. Jiangxi Province: Nanchang City, Meiling Mountain , on decaying bamboo culms submerged in a freshwater stream, alt. 305 m, near 28.79 ° N, 115.72 ° E, 16 August 2021, G. P. Xu, Y. Liu and Z. J. Zhai, SLT- 32 ( HFJAU 10042 , holotype), ex-type living culture, JAUCC 4985 = JAUCC 4986 .

Notes.

Trichobotrys meilingensis is similar to other species of Trichobotrys in having monomatous conidiophores, spherical and echinulate conidia, and polyblastic conidiogenous cells. Trichobotrys meilingensis is easily distinguished from T. effusa , T. ipomoeae and T. trechispora by its dichotomously branched conidiophores and its conidial size (7‒13 μm vs. 3‒4 μm, 13‒15.5 μm and 3‒5 μm, respectively) ( Petch 1917, 1924; Sawada 1959). Trichobotrys meilingensis is morphologically most similar to T. ramosa and shares some characteristics, such as dichotomously branched conidiophores and catenate conidia. However, T. meilingensis has larger conidia (7–13 μm vs. 3‒5 μm) and thinner conidiophores (2.5‒4.5 μm vs. 8‒18 μm) ( D’Souza and Bhat 2001). Therefore, T. meilingensis can be distinguished from T. ramosa based on morphological characters in spite of the unavailable molecular data of the latter species. Thus, it should be identified as an independent taxon in Trichobotrys . A comparison of morphological features of Trichobotrys species is provided in Table 2 .

Figures

Figure 2. Trichobotrys meilingensis (HFJAU 10042, holotype) a, b colonies on bamboo culms c – e conidiophores with conidiogenous cells f portion of conidiophore with fertile lateral branches g, h conidiogenous cells i – n conidia o germinating conidium p, q culture on PDA from above (p) and reverse (q). Scale bars: 100 µm (a, b); 20 µm (c); 5 µm (d ‒ o); 25 mm (p, q).