Apiospora bambusicaulis K. M. Yu & Y. L. Jiang, 2025

Yu, Kunmin, Zhang, Hong, Cheng, Kexin & Jiang, Yulan, 2025, Three new species of Apiospora (Amphisphaeriales, Apiosporaceae) in China, MycoKeys 112, pp. 233-252 : 233-252

Apiospora bambusicaulis K. M. Yu & Y. L. Jiang sp. nov.

Fig. 3

Type.

China • Guizhou Province, Guiyang City , on diseased bamboo branch, 5 June 2022, K. M. Yu, holotype: HGUP 17.41 , other living culture: GUCC 17.42 .

Etymology.

Name refers to the host plant, meaning of bamboo stem, from which this fungus was isolated.

Description.

Asexual morph: On WA, hyphae smooth, branched, septate, hyaline to brown, 1–3.5 µm diam (n = 30). Conidiophores cylindrical, septate, straight to flexuous, sometimes reduced to conidiogenous cells. Conidiogenous cells globose to subglobose, erect, blastic, aggregated in clusters on hyphae, hyaline to pale brown, smooth, branched, 1.5–3.5 × 2–13.5 µm (x = 2.5 × 8 µm, n = 30). Conidia globose, sub-globose to ovate, lenticular, with a longitudinal germ slit over the entire length, brown to dark brown, smooth, 4.5–6 × 5–6 µm (x = 5.5 × 5.5 µm, n = 30). Sexual morph: Not observed.

Culture characteristics.

Colonies on PDA attaining 5 cm diam. after 4 days at 25 ° C, circular, flat, radiating outwards, irregular edge, diffuse yellow pigment, the mycelia white to gray, floccose, cottony, reverse yellow.

Additional specimen examined.

China • Guizhou Province: Huaxi District , on diseased branch of bamboo, June 2023, K. M. Yu, HGUP 17.41 , ex-paratype living culture; living cultures GUCC 17.41 , GUCC 17.42 .

Notes.

The phylogenetic tree indicated that Ap. bambusicaulis is closely related to a clade comprising Ap. thailandica , Ap. jinanensis , and Ap. italica with high support values (ML / BI = 99 / 1) in the multi-locus phylogenetic tree (Fig. 1 ). Ap. bambusicaulis differs from Ap. thailandica (Table 4 ) by 18 nucleotides (13 / 518 in ITS, 2 / 804 in LSU, 2 / 374 in TEF 1 - α, and 1 / 265 in TUB 2), from Ap. italica by 58 nucleotides (17 / 518 in ITS, 4 / 799 in LSU, 26 / 377 in TEF 1 - α, and 11 / 266 in TUB 2), and from Ap. jinanensis by 28 nucleotides (3 / 573 in ITS, 3 / 821 in LSU, 12 / 438 in TEF 1 - α, and 12 / 464 in TUB 2). Morphologically, it differs from Ap. thailandica , Ap. italica , and Ap. jinanensis in conidia (brown, smooth, globose, 4.5–6 × 5–6 µm (x = 5.5 × 5.5 µm, n = 30) in Ap. bambusicaulis vs. globose, subglobose to lenticular, 5–9 × 5–8 μm in Ap. thailandica vs. brown, smooth, globose, (3 –) 4–7 (– 9) × (1.5 –) 2–3 (– 5.0) μm in Ap. italica vs. brown to dark brown, smooth to finely roughened 5.7–6.9 × 5.2–6.7 μm in Ap. jinanensis (Table 3 ), and base pair differences. Therefore, Ap. bambusicaulis is described as a new species, based on phylogeny and morphological comparison.

Figures

Figure 1. Phylogenetic tree of Apiospora, inferred from combined ITS, LSU, TEF 1 - α, and TUB 2 genes. Arthrinium caricicola was used as an outgroup. ML bootstrap support values (≥ 50 %) and Bayesian posterior probability (≥ 0.90) are shown at nodes. Strains in this study are shown in red, and type strains are marked by a “ T ”.

Figure 3. Apiospora bambusicaulis (GUCC 17.41, ex-type culture) A dead bamboo branch with fungi B, C above and below view of the colony on PDA D, E conidia F, G conidiogenous cells giving rise to conidia. Scale bars: 10 µm (D – G).