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

Zhang, Meng-Yuan, Zhang, Zhao-Xue, Wang, Ya-Ling, Zhang, Xiu-Guo & Li, Zhuang, 2025, Molecular and morphological characterization of four new Phyllosticta species (Botryosphaeriales, Phyllostictaceae): Genomic insights into evolutionary dynamics and metabolic adaptation, IMA Fungus 16, pp. e 168055-e 168055 : e168055-

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

Etymology.

The specific epithet “ pittosporicola ” refers to the host plant Pittosporum illicioides .

Type.

CHINA • Yunnan Province, Fengming Mountain, Kunming City (ASL: 1926 m; 25.09°N, 102.76°E), on diseased leaves of Pittosporum illicioides Makino , 29 July 2023, M. Y. Zhang ( holotype HSAUP 5342–3 ), ex-type living culture CGMCC 3.28666 .

Description.

Leaf endogenic and associated with leaves of Pittosporum illicioides Makino. Asexual morph: Conidiomata pycnidial, mostly aggregated in clusters, black, erumpent. In PDA culture exuding colourless to opaque conidial masses within 12 days or longer. Conidiophores indistinct, often reduced to conidiogenous cells. Conidiogenous cells 5.5–10 × 2–4 μm, subcylindrical, ampulliform, hyaline, smooth. Conidia 7–9 × 4–6 μm, hyaline, aseptate, thin and smooth walled, coarsely guttulate, ovoid, ampulliform, ellipsoidal to subglobose, enclosed in a thin mucoid sheath. Sheath 1–2 μm thick and bearing a hyaline, apical mucoid appendage. Appendages 4–7 × 1–2 μm, flexible, unbranched, tapering towards an acutely rounded tip. Spermatia 5–7.5 × 1–2.5 μm, occurring in conidioma with conidia, hyaline, smooth, guttulate to granular, bacilliform. Sexual morph not observed, see Fig. 7 .

Culture characteristics.

Colonies on PDA 18–22 mm in diameter after 7 d at 25 ° C in darkness, with a growth rate of 2.5–3.1 mm / day, undulate at edge, creamy white to black in obverse and reverse.

Additional specimen examined.

CHINA • Yunnan Province, Fengming Mountain, Kunming City (ASL: 1926 m; 25.09°N, 102.76°E), on dead leaves, 29 July 2023, M. Y. Zhang ( HSAUP 5512–4 ), living culture SAUCC 5512–4 .

Notes.

Two isolates from leaf spots of Pittosporum illicioides phylogenetically clustered into a well-supported clade (1.00 / 100), which is closely related to P. concentrica ( CPC 18842 ). However, P. pittosporicola differs from P. elliptica by 55 nucleotides (17 / 571 in ITS, 0 / 0 in LSU, 18 / 406 in tef 1, 18 / 220 in act, and 7 / 615 in gpdh). In morphology, they are distinguished by different hosts ( Clematis vitalba vs. Hedera sp. vs. Kerria japonica ) and shorter conidia in Phyllosticta clematidea than P. concentrica and P. kerriae (7–9 × 4–6 μm vs. (10 –) 11–13 (– 14) × (6 –) 8 (– 9) μm vs. 9.5–12.5 × 6.0–7.5 μm) ( Motohashi et al. 2008; Wikee et al. 2013). Therefore, based on morphology and phylogenetic evidence, we establish this fungus as Phyllosticta pittosporicola sp. nov.

Figures

Figure 7. Phyllosticta pittosporicola (CGMCC 3.28666) a diseased leaf of Pittosporum illicioides b, c colonies (left-above, right-reverse) after 7 days on PDA d conidiomata e, f conidiogenous cells with conidia g, h conidia i spermatia. Scale bars: 10 μm (e – i).