Pestalotiopsis machiliana X. X. Luo and Jian Ma 2024, sp. nov.

Pestalotiopsis machiliana X. X. Luo and Jian Ma sp. nov. Fig. 8 Type. China • Jiangxi Province, Jingdezhen City, Changjiang District, Jingdezhen Botanical Garden; on diseased leaves of Machilus pauhoi; 3 November 2022; X. X. Luo (holotype HJAUP M 1790.221; ex-type living culture HJAUP C 1790.221). Etymology. Referring to the host genus, Machilus from which it was collected. Description. Regular leaf spots, wheat in the center, a black stripe ring in the middle and dark brown at the margin. Asexual morph on PDA: Conidiomata acervular, globose, 646–1584 μm diam., solitary or aggregated in clusters, black. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 18.6–27.2 × 5.6–7.4 μm (x ̄ = 22.5 × 6.5 μm, n = 50), 4 - septate, slightly constricted at the septa; basal cell conical, 3–5.2 μm (x ̄ = 3.9 μm), hyaline or sometimes pale brown, smooth, thin-walled, with a single filiform appendage, unbranched, 4.5–10.2 μm (x ̄ = 8.1 μm) long; three median cells doliiform to cylindrical, smooth, 12.5–17.3 μm (x ̄ = 14.7 μm), concolorous, brown, somewhat constricted at the septa, second cell from the base 3.6–6.7 µm (x ̄ = 5.0 μm) long, third cell 3.8-5.5 µm (x ̄ = 4.6 μm) long, fourth cell 4.1–6.4 µm (x ̄ = 4.9 μm) long; apical cell conical to acute, hyaline, smooth, thin-walled, 3–4.8 µm (x ̄ = 3.9 μm) long, with 2–3 filiform appendages, arising from the apex of the apical cell each at a different point, unbranched, 12.9–22.5 µm (x ̄ = 14.7 μm) long. Sexual morph not observed. Culture characteristics. Colonies on PDA grow fast, reaching 47–53 mm diam. after 5 days at 25 ° C in darkness, white, with flocculent mycelium and entire edge, forming black conidiomata, and reverse buff. Additional specimens examined. China, Jiangxi Province, Jingdezhen City • Changjiang District, Jingdezhen Botanical Garden, 3 November 2022, X. X. Luo. On diseased leaves of Machilus pauhoi, paratype HJAUP M 1790.222, living culture HJAUP C 1790.222 • Fuliang County, Jingdezhen National Forest Park, 2 November 2022, X. X. Luo, on diseased leaves of Rhododendron simsii, paratype HJAUP M 1704.221, living culture HJAUP C 1704.221; on diseased leaves of Rhododendron simsii, paratype HJAUP M 1704.222, living culture HJAUP C 1704.222; on diseased leaves of Rhododendron simsii, paratype HJAUP M 1704.223, living culture HJAUP C 1704.223. Note. Five strains (HJAUP C 1790.221, HJAUP C 1790.222, HJAUP C 1704.221, HJAUP C 1704.222 and HJAUP C 1704.223) of Pestalotiopsis machiliana isolated from leaf spots of Machilus pauhoi clustered as a sister taxon to P. chamaeropis (CFCC 54977, CFCC 55023, CFCC 55019 and CFCC 55122) with 99 % ML / 0.97 BI bootstrap support (Fig. 1). The ex-type strain HJAUP C 1790.221 is closely related to P. chamaeropis (CBS 186.71) and comparisons of their nucleotides showed 8 bp differences (1 %, including one gap) nucleotide differences in three loci. Moreover, P. machiliana is morphologically distinguished from P. chamaeropis Maharachch., K. D. Hyde & Crous, which has minutely verruculose, wider conidia (7–9 μm vs. 5.6–7.4 μm) with longer basal cell (5–6.5 μm vs. 3–5.2 μm) and apical cell (4–6 µm vs. 3–4.8 µm) (Maharachchikumbura et al. 2014).