Biscogniauxia dicranopteridis M.L. Chen, J.Y. Zhang & Y.Z. Lu

Chen, Meng-Lan, Zhang, Jing-Yi, Xiao, Yuan-Pin & Lu, Yong-Zhong, 2024, Biscogniauxia dicranopteridis sp. nov. and B. petrensis isolated from Dicranopteris dichotoma in China, Phytotaxa 641 (4), pp. 255-266 : 260

Biscogniauxia dicranopteridis M.L. Chen, J.Y. Zhang & Y.Z. Lu , sp. nov. FIGURE 2

Index Fungorum number: IF900479. Facesoffungi number: FoF 14894

Etymology—the specific epithet ‘ dicranopteridis’ refers to Dicranopteris , the plant genus from which the type strain was isolated.

Holotype: HKAS 124928

Endophytic in the leaves of Dicranopteris dichotoma . Sexual morph: Undetermined. Asexual morph: Nodulisporium-like. Hyphae hyaline to brown, septate, branched, thin wall, smooth, mycelia abundant. Conidiophores 3.5–5.5 μm (x = 4.5 μm, n = 17) wide, macronematous, mononematous, immersed or semi-immersed, light brown to dark brown, septate, branched at the apex, thin-walled, rough-walled, straight or slightly flexuous, with conidiogenous cells arising terminally or laterally. Conidiogenous cells 6–13 × 3–4.5 μm (x = 9 × 3.5 μm, n = 28), holoblastic, hyaline to brown, terminal on branches, swollen at the apex, thin – walled, verrucous, oblong to ellipsoid. Conidia 5–9 × 2–3.5 μm (x = 6.5 × 2.5 μm, n = 40), aggregated, pleuroacrogenous, hyaline, aseptate, thin-walled, smooth, small guttulate, base bluntly rounded, apex obtuse, obovoid.

Culture characteristics: Colonies grow rapidly on PDA at 25 °C, reaching 50 mm in diameter within 7 days, circular, flat, covered with abundant, lilac grey, lanose aerial mycelia, margin entire; dark brown to orange from center to edge in reverse. Colonies on water agar (WA) medium at 25 °C exhibit thin mycelia with sporulation, slow growth, and branched mycelia at the margin, white from both above and reverse.

Material examined: CHINA, Guizhou Province, Guiyang City, Guiyang Medicinal Botanical Garden , from the healthy leaves of Dicranopteris dichotoma , 13 December 2021, J. Y. Zhang, NS 50-11 (dried culture: HKAS 124928 , holotype; GZAAS 22–2040 , isotype), ex-type culture: KUNCC 23–12692 .

Notes: Phylogenetically, Biscogniauxia dicranopteridis forms a distinct sister clade to B. magna within Biscogniauxia VI , with robust support (94% ML-bs/1.00 BYPP/94% MP-bs). Pairwise nucleotide comparisons reveal differences between B. dicranopteridis and B. magna in 29/604 bp (4.80%) of ITS, 45/1031 bp (4.36%) of RPB2, and 15/890 bp (1.68%) of LSU. Despite their morphological similarity, B. dicranopteridis and B. magna can be distinguished. Conidiogenous cells of B. dicranopteridis are pale brown and verrucose, while those of B. magna are thin- and rough-walled and hyaline. Additionally, B. dicranopteridis exhibits smaller guttulate conidia compared to B. magna ( Samarakoon et al. 2022) .

Figures

FIGURE 2. Biscogniauxia dicranopteridis (HKAS 124928, Holotype) a Culture on PDA from above and below. b Culture on WA from above and below. c Colonies on WA. d, e Conidiophores with conidiogenous cells and conidia.f–i Conidiogenous cells. j–n Conidia.Scale bar: d = 100 μm, e = 50 μm, f–i = 20 μm, j =10 μm, k–n = 5 μm.