Xylolentia bambusae H.J. Zhao, W. Dong & K.D. Hyde, 2025

Zhao, Haijun, Mapook, Ausana, Hyde, Kevin D., Doilom, Mingkwan, Al- Otibi, Fatimah O., Saichana, Natsaran & Dong, Wei, 2025, Xylolentia bambusae (Rhamphoriaceae, Rhamphoriales), a novel species associated with dead bamboo in Guangdong Province, China, Phytotaxa 681 (2), pp. 211-222 : 215-217

Xylolentia bambusae H.J. Zhao, W. Dong & K.D. Hyde , sp. nov. ( Fig. 2 )

Index Fungorum IF 902892, Facesoffungi FoF 16781.

Etymology:— refers to the bamboo host of the holotype.

Holotype:— MHZU 24-0617

Saprobic on dead bamboo culms. Asexual morph: Colonies on wood effuse, hairy, scattered or aggregated, brown, with white glistening conidial masses at the apex. Mycelium partly superficial, partly immersed, composed of septate, smooth-walled, brown to hyaline hyphae. Conidiophores macronematous, mononematous, erect, straight, or slightly flexuous, solitary or aggregated in small groups, cylindrical, smooth-walled, septate, unbranched, mid to dark brown, becoming pale brown to subhyaline at the apex, 57–95 × 2.5–4 µm (= 76 × 3 µm, n = 20), swollen up to 5 µm wide at the base. Conidiogenous cells holoblastic, polyblastic, integrated, terminal, determinate, cylindrical to cylindric-lageniform, pale brown near the base, subhyaline to hyaline towards the apex, 16.5–20 × 2.5–3 µm (= 18.3 × 2.7 µm, n = 20). Conidia acrogenous, aggregated in slimy masses, ellipsoidal, subglobose, aseptate, smooth-walled, hyaline, sometimes guttulate, thin-walled, 3.6–4.8 × 2.1–3.3 µm (= 4.3 × 2.6 µm, n = 50). Sexual morph: undetermined.

Culture characteristics:— conidia germinating on PDA within 24 h. Colonies on PDA reaching 34 mm diam. after 2 weeks at room temperature, dark, circular, raised, with dark brown mycelium on the plicated and waxy-mucoid surface; in reverse view dark brown with entire margin. Conidiophores 46–64 × 3–7 µm (= 53.4 × 4.1 µm, n = 20). Conidiogenous cells elongating percurrent, terminal, determinate, cylindrical, 12–20 × 2.5–5 µm (= 15 × 3.5 µm, n = 20). Conidia ellipsoidal, subglobose to globose, sometimes with 1–2 inconspicuous guttules, 2.5–5 × 2–3.6 µm (= 3.3 × 2.8 µm, n = 50).

Material examined:— CHINA. Guangdong Province: Guangzhou City, Tianhe District, Huolu Mountain Forest Park, 23°10′50″ N, 113°23′13′′ E, on decaying bamboo culms, 29 July 2024, H.J. Zhao, TB004A ( MHZU 24-0617, holotype), ex-type culture ZHKUCC 24-1142.

Notes:— Xylolentia bambusae resembles X. simplex in having cylindrical conidiophores, polyblastic, cylindrical conidiogenous cells, and ellipsoidal conidia. However, X. bambusae has shorter conidiophores than X. simplex (57–95 µm vs. 85–126 µm), and hyaline, ellipsoidal, subglobose conidia, while X. simplex has pale brown, ellipsoidal to reniform conidia ( Kirschner & Hsieh 2023). Nucleotide comparisons of their ITS, LSU, and rpb2 sequences showed 97.96% (14 bp differences, with two gaps), 99.48% (three bp differences) and 96.34% (26 bp differences) similarities, respectively. The SSU and tef1-α sequences are unavailable for X. simplex . Based on morphology and DNA sequence data, X. bambusae is identified as a new species.

Figures

FIGURE 2. Xylolentia bambusae (MHZU 24-0617, holotype). a, b Colony on natural substratum. c Conidiophore and conidia. d, e Conidiogenous cells and conidia. f–l, v Conidia. m, n Culture on PDA, m from above, n from below. o Close-up of the colony texture. p Mycelium. q–u Conidiophores, conidiogenous cells with conidia (polyblastic conidiogenous cell arrow). Scale bars: c–e, p–t = 20 µm, f–l, v = 5 µm, u = 10 µm.