Bambusicola gelatinosospora Y. Feng, Z. Y. Liu & Jian K. Liu, 2025

Feng, Yao, Chen, Ya-Ya, Lin, Chuan-Gen, Liu, Zuo-Yi, Chen, Xiao-Fang, Pei, Guo-Shun & Liu, Jian-Kui, 2025, Morpho-phylogenetic evidence reveals novel Bambusicolous fungi from Guizhou Province, China, MycoKeys 118, pp. 81-103 : 81-103

Bambusicola gelatinosospora Y. Feng, Z. Y. Liu & Jian K. Liu sp. nov.

Fig. 3

Holotype.

HKAS 112599.

Etymology.

The epithet refers to the gelatinous sheath of ascospores.

Description.

Saprobic on dead bamboo culms, forming raised, black spots on the host surface. Sexual morph: Ascomata 320–345 μm diam, 170–230 μm high, solitary, scattered to gregarious, immersed, subglobose with a flattened base. Peridium comprising several layers of cells of textura angularis, less distinguished from the host tissue. Hamathecium of dense, 1–2 μm wide, filamentous, branched, septate, smooth-walled, trabecular pseudoparaphyses, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci 60–90 × 10–12 μm (x ̄ = 77 × 11 μm, n = 20), 8 - spored, bitunicate, fissitunicate, broadly cylindrical to cylindrical-clavate, with a short pedicel, apically rounded with a well-developed ocular chamber. Ascospores (16 –) 20–25 × 4–6 μm (x ̄ = 22 × 5 μm, n = 30), overlapping, biseriate, hyaline, fusiform, slightly bent with acute ends, 3 - septate, slightly constricted at the septa, smooth-walled, guttulate, surrounded by a gelatinous sheath. Asexual morph: Undetermined.

Culture characteristics.

Colonies on PDA slow growing, reaching 15 mm diam. after 10 d at 25 ° C in dark. circular, felted, with white dense mycelium on the surface. In reverse pale yellow, becoming brown from the center, with an entire margin.

Material examined.

China • Guizhou Province, Xingyi City . On dead stem of bamboo, 5 September 2019, Yao Feng, XY 19-11 ( HKAS 112599 , holotype; GZAAS 21-0502 , isotype), ex-type living cultures CGMCC 3.20355 = GZCC 21-0802 ; ibid., on dead branches on bamboo, 5 September 2019, Yao Feng, XY 19 a ( GZAAS 21-0390 ; paratype), living cultures GZCC 21-0898 .

Notes.

Phylogenetic analyses revealed that the two strains of Bambusicola gelatinosospora (CGMCC 3.20355 and GZCC 21-0898) clustered with B. thailandica (MFLUCC 11-0147) and B. subthailandica (SICAUCC 16-0005) as a distinct lineage (Fig. 1 ). Morphologically, B. gelatinosospora closely resembles B. thailandica and B. subthailandica , sharing key characteristics such as ostiolate ascomata, cylindrical to cylindri-clavate asci, and hyaline, fusiform, 3 - septate ascospores with acute ends ( Dai et al. 2017; Yang et al. 2019). Although these species are morphologically indistinguishable, their cultures exhibit differences in colors and colony morphology (Table 2 ). Additionally, they can be differentiated by their minimal sequence similarities. In a comparison of ITS, LSU, rpb 2 and tef 1 - α nucleotides, B. gelatinosospora (CGMCC 3.20355) has 98 %, 99 %, 97 % and 99 % similarity, in ITS (702 / 713 bp, 1 gap), LSU (817 / 819 bp, no gaps), rpb 2 (949 / 974 bp, no gaps), and tef 1 - α (914 / 920 bp, no gap), which is different from B. thailandica (MFLUCC 11-0147). These findings combined with its morphological and molecular distinctiveness strongly supported the conclusion that Bambusicola gelatinosospora represents a new species within the genus Bambusicola .

Figures

Figure 1. Phylogram generated from maximum likelihood analysis based on a combined dataset of SSU, ITS, LSU, rpb 2 and tef 1 - α sequences. Bootstrap support values for ML (≥ 75 %) and bayesian posterior probabilities (≥ 0.95) are given at the nodes (ML BS / PP). Branches with 100 % ML BS and 1.00 PP are thickened. New strains are shown in red. The tree is rooted with Sulcatispora berchemiae KT 1607 and Sulcatispora acerina KT 2982, and ex-type strains are in bold.

Figure 3. Bambusicola gelatinosospora (HKAS 112599, holotype) A, B appearance of ascomata on the host C vertical section of an ascoma D pseudoparaphyses E germinated ascospores F, G cultures on PDA F from above G from below H – L asci M – Q ascospores. Scale bars: 100 µm (C); 30 µm (E); 20 µm (H – L); 15 µm (D, M – Q).