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 .