Pestalotiopsis fraseri M. G. Liao & Jian Ma 2026, sp. nov.

Pestalotiopsis fraseri M. G. Liao & Jian Ma sp. nov. Fig. 4 Type. China • Jiangxi Province, Nanchang City, Jiangxi Agricultural University, on diseased leaves of Photinia × fraseri Dress, 26 October 2023, X. X. Luo (HJAUP M 1693, holotype), ex-type living culture HJAUP C 1693.1 = HJAUP C 1693.2 = HJAUP C 1693.3 = HJAUP C 1693.4. Etymology. Named after the host species, Photinia × fraseri, from which the fungus was isolated. Description. Regular leaf spots, pale brown in center with brown at margin. Asexual morph on PDA: Conidiomata acervular, globose to clavate, 426–786 μm diam., solitary, black. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 19.3–26.4 × 5.2–6.3 μm (x ̄ = 23.0 × 5.7 μm, n = 50), 4 - septate, slightly constricted at the septa; basal cell conical, 3.4–5.3 μm (x ̄ = 4.4 μm), hyaline, smooth, thin-walled, with a single filiform appendage, unbranched, 4.6–10.5 μm (x ̄ = 7.9 μm) long; three median cells doliiform to cylindrical, smooth, thick-walled, 12.2–16.2 μm (x ̄ = 14.4 μm), concolorous, brown, somewhat constricted at the septa, second cell from the base 3.9–6.1 µm (x ̄ = 4.8 μm) long, third cell 4.0–5.4 µm (x ̄ = 4.7 μm) long, fourth cell 4.0–5.2 µm (x ̄ = 4.7 μm) long); apical cell conical to acute, hyaline, smooth, thin-walled, 3.7–5.0 µm (x ̄ = 4.2 μm) long, with 2–3 filiform appendages, arising from the apex of the apical cell each at a different point, unbranched, 12.3–20.8 µm (x ̄ = 16.3 μm) long. Sexual morph: not observed. Culture characteristics. Colonies on PDA grow fast, filamentous, reaching 85–90 mm diam. after 5–7 days at 25 ° C in light and dark conditions (8 h / 16 h), white, with flocculent mycelium and entire edge, forming black conidiomata, and reverse white. Note. Phylogenetic analyses revealed that the four strains (HJAUP C 1693.1 T, HJAUP C 1693.2, HJAUP C 1693.3, and HJAUP C 1693.4) of P. fraseri form a distinct clade sister to P. koelreuteriae (HJAUP C 2757.1 T and HJAUP C 2757.2) with 100 % ML / 1.00 BI bootstrap support (Fig. 1). Based on a BLASTn search of P. fraseri (HJAUP C 1693.1 T) and P. koelreuteriae (HJAUP C 2757.1 T) in GenBank, comparisons of nucleotides showed 13 bp (619 / 632, including three gaps), 1 bp (296 / 297, no gaps), and 3 bp (479 / 482, including one gap) nucleotide differences in the ITS, tef 1-α, and tub 2 regions, respectively. Based on a BLASTn search of P. fraseri (HJAUP C 1693.1 T) and P. trachycarpicola (OP 068 T) in GenBank, comparisons of nucleotides showed 10 bp (530 / 540, including one gap) and 1 bp (294 / 295, no gaps) in the ITS and tef 1-α regions, respectively. Moreover, P. fraseri differs from P. koelreuteriae (this study) in its conidia with longer basal appendages (4.6–10.5 μm vs. 3.4–6.7 μm) and longer apical appendages (12.3–20.8 µm vs. 8.1–18.5 µm), and from P. trachycarpicola Yan M. Zhang & K. D. Hyde (Zhang et al. 2012 b) in its longer basal appendages (4.6–10.5 μm vs. 2.7–5.5 μm). Furthermore, P. fraseri can be distinguished from P. koelreuteriae and P. trachycarpicola by its different host (Photinia × fraseri vs. Koelreuteria paniculata vs. Trachycarpus fortunei).