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

Fig. 3

Type.

China • Jiangxi Province, Jingdezhen City, Changjiang District, Jingdezhen Botanical Garden , on diseased leaves of Camellia japonica , 3 November 2022, X. X. Luo (holotype HJAUP M 1804.221 ; ex-type living culture HJAUP C 1804.221 ) .

Etymology.

Referring to the host genus from which it was collected, Camellia japonica .

Description.

Regular leaf spots, grey white in the center, and brown to dark brown at the margin. Asexual morph on PDA: Conidiomata acervular, 470–1320 μm diam., superficial, solitary or aggregated in clusters, dark brown. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 14.9–22.2 × 5.4–7.6 μm (x ̄ = 18.1 × 6.3 μm, n = 50), 4 - septate, mostly with one minute guttules in each cell, slightly constricted at the septa; basal cell conical, 1.8–4 μm (x ̄ = 2.8 μm), pale brown, smooth, thin-walled, with a single filiform appendage, unbranched, 1.7–5.2 μm (x ̄ = 2.9 μm) long; three median cells doliiform to cylindrical, smooth, 11–14.4 μm (x ̄ = 12.4 μm), concolorous, pale brown to brown, somewhat constricted at the septa, second cell from the base 3.8–5.3 µm (x ̄ = 4.3 μm) long, third cell 3.6–4.7 µm (x ̄ = 4.2 μm) long, fourth cell 3.2–5 µm (x ̄ = 4 μm) long); apical cell conical to acute, hyaline, smooth, thin-walled, 2.2–3.8 µm (x ̄ = 2.9 μm) long, with 2–4 (mostly 3) filiform appendages, arising from the apical crest, branched, 9.5–20.3 µm (x ̄ = 12.4 μm) long. Sexual morph: not observed.

Culture characteristics.

Colonies on PDA grow fast, filamentous, reaching 56–62 mm diam. after 5 days at 25 ° C in darkness, white, with flocculent mycelium and entire edge, forming black, brown conidiomata, and reverse pale orange.

Additional specimen examined.

China • Jiangxi Province, Jingdezhen City, Changjiang District, Jingdezhen Botanical Garden , 3 November 2022, X. X. Luo. On diseased leaves of Camellia japonica , paratype HJAUP M 1804.222 , living culture HJAUP C 1804.222 .

Note.

Two strains ( HJAUP C 1804.221 and HJAUP C 1804.222 ) of Pestalotiopsis camelliicola isolated from leaf spots of Camellia japonica formed a distinct clade sister to P. portugalica ( CBS 393.48) with 100 % ML / 1.00 BI bootstrap support (Fig. 1 ). The ex-type strain HJAUP C 1804.221 is closely related to P. portugalica ( CBS 393.48) and comparisons of their nucleotides showed 20 bp differences (2 %, including four gaps) nucleotide differences in three loci. Moreover, P. camelliicola is morphologically distinguished from P. portugalica Maharachch., K. D. Hyde & Crous in its solitary or scattered conidiomata and conidia with more apical filiform appendages (2–4 vs. 1–3). In addition, the conidia of P. camelliicola usually have one minute guttule at each cell, which are not observed in P. portugalica ( 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 3. Pestalotiopsis camelliicola (HJAUP C 1804.221, 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).