Macroidriella bambusae Z. X. Zhang & X. G. Zhang, 2024

Zhang, Zhao-Xue, Shang, Yu-Xin, Zhang, Meng-Yuan, Zhang, Jin-Jia, Geng, Yun, Xia, Ji-Wen & Zhang, Xiu-Guo, 2024, Phylogenomics, taxonomy and morphological characters of the Microdochiaceae (Xylariales, Sordariomycetes), MycoKeys 106, pp. 303-325 : 303-325

Macroidriella bambusae Z. X. Zhang & X. G. Zhang sp. nov.

Fig. 4

Type.

China, Hainan Province, Danzhou City: Hainan tropical botanical garden, on diseased leaves of Bambusaceae sp., 15 October 2023, Z. X. Zhang ( HMAS 352974, holotype), ex-holotype living culture SAUCC 6792-1.

Etymology.

Referring to the species name of the host plant Bambusaceae sp.

Description.

Endogenic on diseased leaves of Bambusaceae sp. Mycelia are superficial and immersed, 2–3.5 µm wide, branched, membranous and hyaline. Sporodochia yellowish brown, slimy. Conidiophores are indistinct and often reduced to conidiogenous cells. Conidiogenous cells are straight or slightly curved, 10.4–15 × 1.7–2.8 µm, mono- or polyblastic, terminal, hyaline, septate, cylindrical and smooth. Conidia are solitary, hyaline, lunate, curved, mooned, 16.5–21.7 × 2–2.8 µm, multi-guttulate, apex rounded, base usually flattened. Sexual morphs were not observed, chlamydospores were not observed, see Fig. 4 .

Culture characteristics.

Cultures incubated on PDA at 25 ° C in darkness, reaching 63–70 mm diam., had a growth rate of 4.5–5.0 mm / day after 14 days, with moderate aerial mycelia, the center and edges are milky white, with a yellow-brown color in the middle, and sporodochia are observed.

Additional material studied.

China, Hainan Province, Danzhou City, Hainan tropical botanical garden, on diseased leaves of Bambusaceae sp., 15 October 2023, Z. X. Zhang ( HSAUP 6792-2), living culture SAUCC 6792-2; ibid, ( HSAUP 6792-5), living culture SAUCC 6792-5; on dead leaves, 15 October 2023, Z. X. Zhang ( HSAUP 6113-1), living culture SAUCC 6113-1; ibid., ( HSAUP 6113-3), living culture SAUCC 6113-3.

Notes.

Phylogenetic analyses showed that Macroidriella bambusae formed an independent clade (Fig. 1 ), and closely related to Idriella multiformispora (lunate, curved-shaped conidia) and Microdochium bolleyi . The Ma. bambusae was distinguished from I. multiformispora ( CGMCC 3.20779) by 60 / 520, 22 / 1222, 74 / 848 and 57 / 710 base-pair differences, from Mi. bolleyi ( CBS 540.92) by 40 / 514, 19 / 765, 138 / 850 and 51 / 710 base pairs in ITS, LSU, RPB 2 and TUB 2 sequences, respectively. Morphologically, Ma. bambusae (16.5–21.7 × 2–2.8 µm) longer than I. multiformispora (8.5–13.5 × 1.0–2 µm) and Mi. bolleyi (5–8.7 × 1.6–2.3 µm) in conidia. Therefore, we describe this fungus as a novel species.

Figures

Figure 1. A maximum likelihood tree was constructed using a combined dataset of ITS, LSU, RPB 2, and TUB 2 sequence data. Branch support values, shown as ML / BIPP, are indicated above the nodes: MLBV ≥ 70 % on the left and BIPP ≥ 0.90 on the right. Ex-type cultures are denoted in bold and marked with an asterisk (*). Strains from the current study are highlighted in red. The tree was rooted with Cryptostroma corticale (CBS 218.52). The scale bar at the bottom center represents 0.05 substitutions per site.

Figure 4. Macroidriella bambusae (HMAS 352974, holotype) a a leaf of Bambusaceae sp. b, c colonies on PDA from above and below after 14 days d colony overview e, f conidiogenous cells and conidia g, h conidia. Scale bars: 10 μm (e – h).