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

Luo, Xing-Xing, Liao, Ming-Gen, Zhang, Kai, Castañeda-Ruíz, Rafael F., Ma, Jian & Xu, Zhao-Huan, 2024, Morphological and phylogenetic analyses reveal eight novel species of Pestalotiopsis (Sporocadaceae, Amphisphaeriales) from southern China, MycoKeys 109, pp. 207-238 : 207-238

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).

Figures

Figure 1. Phylogenetic relationship of Pestalotiopsis based on concatenated sequences of ITS, tef 1 - α and tub 2 sequence data. The ML and BI bootstrap support values above 80 % and 0.80 are given above the nodes. Bar = 0.03 substitution per nucleotide position. The tree is rooted to Nonappendiculata quercina (CBS 116061) and N. quercina (CBS 270.82). The strains from the present study are marked in red. Some branches are shortened according to the indicated multipliers to fit the page size, and these are indicated by the symbol (//).

Figure 8. Pestalotiopsis machiliana (HJAUP C 1790.221, ex-type) a, b leaf of host plant (front and reverse) c, d culture on PDA (front and reverse) e – g conidiomata h, i conidiogenous cells and conidia j – q conidia. Scale bars: 200 µm (f, g); 10 µm (h – q).