Beltraniella dujiangyanensis W. W. Liu, C. Z. Yin, Z. X. Zhang & X. G. Zhang, 2025

Liu, Wen-Wen, Yin, Chang-Zhun, Zhang, Zhao-Xue, Wang, Xing-Sheng, Meng, Zhe, Zhang, Xiu-Guo & Wang, Shi, 2025, Four new species of Beltraniella (Amphisphaeriales, Beltraniaceae) revealed by morphology and phylogenetic analyses from China, MycoKeys 116, pp. 125-144 : 125-144

Beltraniella dujiangyanensis W. W. Liu, C. Z. Yin, Z. X. Zhang & X. G. Zhang sp. nov.

Fig. 2

Holotype.

China • Sichuan Province, Dujiangyan City , 30°57'53"N, 103°35'13"E, on decaying leaves, 24 June 2023, W. W. Liu, holotype HMAS 352921 , ex-type living culture SAUCC 427003 .

Etymology.

The epithet “ dujiangyanensis ” denotes the geographical origin of the strains, namely, Dujiangyan City.

Description.

Parasitic on decaying leaves. Asexual morph: Setae unbranched, straight or flexuous, single, dark brown, subulate, thick-walled, tapering to a pointed apex, 9–10 septate, verrucose, dark brown, swollen, arising from a radially lobed basal cell, 83.9–150.2 × 3.0–5.4 µm. Conidiophores hyaline, presenting two distinct forms: long and short. Long conidiophores arise from lobed basal cells, macronematous, erect, straight or slightly curved, either simple or rarely branched, septate, verrucose, dark-brown, apical part lighter, arising from basal cells of setae or from separate cells, 113.1–259.9 × 3.1–5.8 μm. Short conidiophores hyaline, septate, smooth edges, simple or branched, 13.1–31.9 × 3.2–5.7 µm. Conidiogenous cells polyblastic, integrated, determinate, cylindrical, smooth, terminal, geniculate, denticulate, hyaline to subhyaline, 5.5–10.9 × 2.9–4.7 µm. Separating cells ellipsoid to subglobose, smooth, subhyaline, single, denticle at each end, 9.7–12.3 × 3.1–5.3 µm. Conidia originate directly from the conidiogenous cells in the long conidiophores and from the separating cells in the short ones. Conidia arise directly from conidiogenous cells or from separating cells, simple, teardrop-shaped, sometimes verrucose, narrow-tipped, terminal, hyaline, smooth, straight, rostrate to pointed at proximal end, truncate at distal end, 16.5–21.1 × 4.2–8.5 µm. Sexual morph: Inconclusive.

Culture characteristics.

On PDA medium, after seven days of dark incubation in a 25 ° C incubator, colonies reached 68 mm in diameter with a growth rate of 9.2–10.2 mm / day. Colonies on PDA medium were concentric, flatter, white, moderately dense, granular surface, sparse aerial mycelia, with mycelium in the middle portion aggregated into a circle and mycelium on the edges dispersed to form a fluffy shape; reverse, pale yellow to white, fluffy edges.

Additional material studied.

China • Sichuan Province, Dujiangyan City , 30°57'53"N, 103°35'13"E, on decaying leaves, 24 June 2023, W. W. Liu, HSAUP 427004 , living culture SAUCC 427004 .

Notes.

Based on the phylogenetic tree constructed using ITS and LSU sequence data, Beltraniella dujiangyanensis was identified as the closest relative to B. xinglongensis sp. nov., with 90 % MLBS and 0.99 BPP support values (Fig. 1 ). Additionally, there is a disparity of 16 / 502 bp between their ITS sequences. Morphologically, B. dujiangyanensis differed from B. xinglongensis in having shorter long conidiophores ( B. dujiangyanensis : 113.1–259.9 × 3.1–5.8 μm vs. B. xinglongensis : 232.5–298.6 × 2.4–4.9 μm) and fewer septa ( B. dujiangyanensis : 9–10 septa vs. B. xinglongensis : 13–15 septa), shorter in short conidiophores ( B. dujiangyanensis : 13.1–31.9 × 3.2–5.7 μm vs. B. xinglongensis : 21.2–47.8 × 3.2–6.4 μm), shorter separating cells ( B. dujiangyanensis : 9.7–12.3 × 3.1–5.3 μm vs. B. xinglongensis : 13.6–17.6 × 2.3–5.4 μm) and shorter conidia ( B. dujiangyanensis : 16.5–21.1 × 4.2–8.5 μm vs. B. xinglongensis : 21.9–28.7 × 5.0–9.5 μm). As a result, B. dujiangyanensis was identified as a new species of Beltraniella by phylogenetic analysis and morphological comparison.

Figures

Figure 1. Phylogenetic tree of Beltraniella based on combined ITS and LSU sequences. Bootstrap support values exceeding 70 % (ML) and 0.90 (BI) are indicated by MLBS / BPP, and new species are highlighted in red. Branches separated by gray and yellow indicate different species of Beltraniella and Beltrania. The lines in the lower right-hand corner represent changes of 0.01 nucleotides per site.

Figure 2. Beltraniella dujiangyanensis (holotype: HMAS 352921) a, b colony front and back after 7 days culture on PDA c setae d long conidiophores e short conidiophores f separating cells and conidia. Scale bars: 10 μm (c – f).