Pestalotiopsis cyclosora X. X. Luo & Jian Ma 2024, sp. nov.

Pestalotiopsis cyclosora X. X. Luo & Jian Ma sp. nov. Fig. 4 Type. China • Jiangxi Province, Xinyu City, Yushui District, Baoshi Park, on diseased leaves of Cyclosorus interruptus, 2 November 2022, X. X. Luo (holotype HJAUP M 1724.221; ex-type living culture HJAUP C 1724.221). Etymology. Referring to the host genus, Cyclosorus from which it was collected. Description. Regular leaf spots, yellowish to grey white in the center, and dark brown at the margin. Asexual morph on PDA: Conidiomata acervular, globose, 460–780 μm diam., solitary, black. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 16.3-26.1 × 5.4–7.1 μm (x ̄ = 21.3 × 6.4 μm, n = 50), 4 - septate, slightly constricted at the septa; basal cell conical, 2.7–4.7 μm (x ̄ = 3.5 μm), hyaline or sometimes pale brown, smooth, thin-walled, with a single filiform appendage, unbranched, 4.1–10.6 μm (x ̄ = 7.7 μm) long; three median cells doliiform to cylindrical, smooth, 11–17.1 μm (x ̄ = 14.1 μm), concolorous or sometimes darker at the two upper cells, somewhat constricted at the septa, second cell from the base brown, 3.9–6.2 µm (x ̄ = 4.8 μm) long, third cell brown to dark brown, 3.9-5.6 µm (x ̄ = 4.7 μm) long, fourth cell brown, 3.8–5.7 µm (x ̄ = 4.8 μm) long); apical cell conical to acute, hyaline, smooth, thin-walled, 2.6–4.2 µm (x ̄ = 3.6 μm) long, with 1–4 (mostly 2 or 3) filiform appendages, arising from the apical crest, sometimes branched, 12.5–29.8 µm (x ̄ = 20.1 μm) long. Sexual morph not observed. Culture characteristics. Colonies on PDA grow fast, filamentous to circular, reaching 62–69 cm diam. after 5 days at 25 ° C in darkness, regular edge, white, with filamentous aerial mycelium and entire edge, and reverse pale orange. Additional specimen examined. China • Jiangxi Province, Xinyu City, Yushui District, Baoshi Park, 2 November 2022, X. X. Luo. On diseased leaves of Cyclosorus interruptus, paratype HJAUP M 1724.222, living culture HJAUP C 1724.222; on diseased leaves of Microlepia marginata, paratype HJAUP M 1725.221, living culture HJAUP C 1725.221; on diseased leaves of Microlepia marginata, paratype HJAUP M 1725.222, living culture HJAUP C 1725.222 • Yingtan City, Guixi County, Shangqing Town, Longhu Mountain National Forest Park, 3 November 2022, X. X. Luo. On diseased leaves of Punica granatum, paratype HJAUP M 1726.221, living culture HJAUP C 1726.221; on diseased leaves of Punica granatum, paratype HJAUP M 1726.222, living culture HJAUP C 1726.222. Notes. Six strains (HJAUP C 1724.221, HJAUP C 1724.222, HJAUP C 1725.221, HJAUP C 1725.222, HJAUP C 1726.221 and HJAUP C 1726.222) of Pestalotiopsis cyclosora isolated from leaf spots of Cyclosorus interruptus, Microlepia marginata and Punica granatum clustered as a sister taxon to the clade containing P. ficicrescens (HGUP 861) and P. biciliata (CBS 124463 and CBS 236.38) with 90 % ML / 0.97 BI bootstrap support (Fig. 1). The ex-type strain HJAUP C 1724.221 is closely related to P. ficicrescens (HGUP 861) and P. biciliata (CBS 124463), and comparisons of their nucleotides showed 18 bp differences (2 %, including three gaps) and 12 bp differences (1 %, including two gaps) nucleotide differences in three loci, respectively. Moreover, P. cyclosora is morphologically distinguished from P. ficicrescens Qi Yang & Yong Wang bis in its conidia with darker median cells and longer filiform appendages at both ends (apical appendages: 12.5–29.8 µm vs. 10.5–18 µm, basal appendage: 4.1–10.6 μm vs. 3.5–7 µm), and more apical appendages (1–4 vs. 2–3) in apical cell (Hyde et al. 2023). Pestalotiopsis cyclosora is also different from P. biciliata Maharachch., K. D. Hyde & Crous, which has verruculose conidia with concolourous, olivaceous median cells and longer basal cell (4–7 μm vs. 2.7–4.7 μm) bearing two appendages (Maharachchikumbura et al. 2014).