Pestalotiopsis gardeniae X. X. Luo & 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 gardeniae X. X. Luo & Jian Ma sp. nov.

Fig. 6

Type.

China • Jiangxi Province, Yingtan City, Guixi County, Shangqing Town, Longhu Mountain National Forest Park , on diseased leaves of Gardenia jasminoides , 23 June 2022, X. X. Luo (holotype HJAUP M 1729.221 ; ex-type living culture HJAUP C 1729.221 ) .

Description.

Regular leaf spots, grey white in center, and pale brown at margin with yellowish halo. Asexual morph on PDA: Conidiomata acervular, globose or subglobular, 763–955 μm diam., solitary or aggregated, black. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 17.4–25.4 × 5.3–6.7 μm (x ̄ = 21.9 × 6 μm, n = 50), 4 - septate, slightly constricted at the septa; basal cell conical, 3.4–6.4 μm (x ̄ = 5.1 μm), pale brown to subhyaline, smooth, thin-walled, with a single filiform appendage, unbranched, 2.9–4.7 μm (x ̄ = 3.9 μm) long; three median cells doliiform to cylindrical, 11–14.7 μm (x ̄ = 13.2 μm), concolorous or sometimes darker at the central cell or the two upper cells, somewhat constricted at the septa, second cell from the base pale brown, 3.4–5.1 (x ̄ = 4.3 μm) µm long, third cell medium to dark brown, 3.7–5.3 µm (x ̄ = 4.4 μm) long, fourth cell pale to medium brown, 3.7–5.4 µm (x ̄ = 4.5 μm) long; apical cell conical to acute, hyaline, smooth, thin-walled, 2.9–4.3 µm (x ̄ = 3.6 μm) long, with 2–3 (mostly 3) filiform appendages, arising from the apical crest, unbranched, 10–20.6 µm (x ̄ = 14.4 μm) long. Sexual morph not observed.

Culture characteristics.

Colonies on PDA grow fast, filamentous to circular, reaching 70–75 mm diam. after 5 days at 25 ° C in darkness, white, with flocculent aerial mycelium and entire edge, forming black conidiomata, and reverse pale orange.

Additional specimen examined.

China • Jiangxi Province, Yingtan City, Guixi County, Shangqing Town, Longhu Mountain National Forest Park , 23 June 2022, X. X. Luo. On diseased leaves of Gardenia jasminoides , paratype HJAUP M 1729.222 , living culture HJAUP C 1729.222 ; on diseased leaves of Gardenia jasminoides , paratype HJAUP M 1729.223 , living culture HJAUP C 1729.223 .

Note.

Three strains ( HJAUP C 1729.221 , HJAUP C 1729.222 and HJAUP C 1729.223 ) of Pestalotiopsis gardeniae isolated from leaf spots of Gardenia jasminoides formed a distinct clade sister to P. sichuanensis ( SA 3 A 21) with 100 % ML / 1.00 BI bootstrap support (Fig. 1 ). The ex-type strain HJAUP C 1729.221 is closely related to P. sichuanensis ( SA 3 A 21) and comparisons of their nucleotides showed 3 bp differences (1 %, including zero gap) nucleotide differences in three loci. Moreover, P. gardeniae is morphologically distinguished from P. sichuanensis Y. C. Wang, X. C. Wang & Y. J. Yang in its larger conidia (17.4–25.4 × 5.3–6.7 μm vs. 8.6–12.5 × 2.6–3.7 μm) with longer apical filiform appendages (10–20.6 μm vs. 2.6–9.2 μm) ( Wang et al. 2019).

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 6. Pestalotiopsis gardeniae (HJAUP C 1729.221, 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 – o conidia. Scale bars: 200 µm (f, g); 10 µm (h – o).