Phyllosticta elliptica M. Y. Zhang, Z. X. Zhang & X. G. Zhang, 2025

Zhang, Meng-Yuan, Zhang, Zhao-Xue, Li, Du-Hua, Zhang, Xiu-Guo, Xia, Ji-Wen & Li, Zhuang, 2025, Morphological and phylogenetic analysis reveal three new species Phyllosticta (Phyllostictaceae, Botryosphaeriales) in China, MycoKeys 118, pp. 35-54 : 35-54

Phyllosticta elliptica M. Y. Zhang, Z. X. Zhang & X. G. Zhang sp. nov.

Fig. 3

Etymology.

The specific epithet “ elliptica ” refers to the genus name of the host plant Rubus ellipticus var. obcordatus .

Type.

China • Yunnan Province, Hongta District, Yuxi City, Longma Mountain Scenic Area , on diseased leaves of Rubus ellipticus var. obcordatus (Franch.) Focke , 12 May 2024, M. Y. Zhang (holotype HSAUP 8332 ), ex-type living culture CGMCC 3.28672 .

Description.

Leaf endogenic and associated with leaves of Rubus ellipticus var. obcordatus . Sexual morph: Not observed. Asexual morph: Conidiomata pycnidial, mostly aggregated in clusters, black, erumpent. In PDA culture, exuding white conidial masses within 15 days or longer. Pycnidial walls multilayered, textura angularis, brown, inner walls of hyaline. Conidiophores indistinct, often reduced to conidiogenous cells. Conidiogenous cells 7–15 × 1.8–4 μm, cylindrical, hyaline, smooth. Conidia 12–15 × 7.5–11 μm (L / W 1.17 –1.54), ovoid, ampulliform, ellipsoidal to subglobose, hyaline, aseptate, thin and smooth walled, multi-guttulate, or with a single large central guttule, surrounded by a mucilaginous sheath. Sheath 1.3–1.8 μm thick, thicker on both sides, and bearing a hyaline, apical mucoid appendage. Appendages 4–12 × 1–1.2 μm, flexible, unbranched, tapering towards an acutely rounded tip.

Culture characteristics.

Colonies on PDA 33–36 mm in diameter after 14 d at 25 ° C in darkness, with a growth rate of 2.3–2.6 mm / day, undulate at edge, creamy white to black in obverse and reverse.

Additional specimen examined.

China • Yunnan Province, Hongta District, Yuxi City, Longma Mountain Scenic Area , on dead leaves, 12 May 2024, M. Y. Zhang ( HSAUP 8331 ), living culture SAUCC 8331–2 .

Notes.

Phyllosticta elliptica is closely related to P. aucubae-japonicae ( MAFF 236703 ) and P. gwangjuensis ( CNUFC NJ 1–12 and CNUFC NJ 1-12 - 1) based on DNA sequence data in BLAST searches and phylogenetic analysis (Fig. 1 ). However, P. elliptica differs from P. aucubae-japonicae by 70 nucleotides (31 / 628 in ITS, 0 / 737 in LSU, 22 / 266 in tef, 17 / 239 in ACT, and 0 / 725 in GPDH) and from P. gwangjuensis by 60 nucleotides (25 / 634 in ITS, 0 / 737 in LSU, 16 / 376 in tef 1, 19 / 214 in ACT, and 0 / 725 in GPDH). In morphology, they are distinguished by different hosts ( Rubus ellipticus var. obcordatus vs. Aucuba japonica vs. Torreya nucifera ) and longer conidia in Phyllosticta elliptica than in P. aucubae-japonicae and P. gwangjuensis (12–15 × 7.5–11 μm (L / W 1.17 –1.54) vs. 10–13 × 5–8.5 μm (L / W 1.41 –1.65) vs. (8.5 –) 10–13.5 × 7–9 (– 9.5) μm (L / W 1.40 –1.53 )) ( Hernandez-Restrepo et al. 2016; Nguyen et al. 2022). Therefore, based on morphology and phylogenetic evidence, we establish this fungus as Phyllosticta elliptica sp. nov.

Figures

Figure 1. Phylogram of the Phyllosticta, inferred from a concatenated alignment of ITS, LSU, tef 1, ACT, and GPDH sequences. Botryosphaeria obtusa (CMW 8232) and B. stevensii (CBS 112553) were used as outgroup taxa. BI posterior probabilities and ML bootstrap support values above 0.90 and 70 % are shown at the first and second positions, respectively. Ex-type cultures are highlighted in bold, while strains obtained in this study are marked in red. Some branches have been shortened for layout optimization, indicated by double diagonal lines with the corresponding reduction factor. The scale bar at the bottom left represents the number of substitutions per site.

Figure 3. Phyllosticta elliptica (CGMCC 3.28672) a diseased leaf of Rubus ellipticus var. obcordatus b, c colonies (left-above, right-reverse) after 14 d on PDA d conidiomata e, f conidiogenous cells with conidia g – j conidia. Scale bars: 10 μm (e – j).