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

Etymology.

The specific epithet “ clematidea ” refers to the host plant Clematis vitalba .

Type.

CHINA • Yunnan Province, Yuxi City, Bailongtan Park , on diseased leaves of Clematis vitalba L., 12 May 2024, M. Y. Zhang ( holotype HSAUP 8121–1 ), ex-type living culture CGMCC 3.28671 .

Description.

Leaf endogenic and associated with leaves of Clematis vitalba . Asexual morph: Conidiomata pycnidial, mostly aggregated in clusters, black, erumpent, globose to clavate or elongated, exuding opaque to withe conidial masses, it exudes write conidial masses within 12 days or longer. Conidiophores indistinct, often reduced to conidiogenous cells. Conidiogenous cells 10–18 × 2–4.5 μm, subcylindrical, hyaline, smooth, proliferating several times percurrently near apex. Conidia 8–11.5 × 6–10 (5.5–7.5) μm, solitary, hyaline, aseptate, thin and smooth walled, coarsely guttulate, or with a single large central guttule, ovoid to irregularly ellipsoid, surrounded by a mucilaginous sheath. Sheath 1–2 μm thick, and bearing a hyaline apical mucoid appendage. Appendages 2.5–6 × 1 μm, flexible, unbranched, tapering towards an acutely rounded tip. Sexual morph not observed, see Fig. 6 .

Culture characteristics.

Colonies on PDA 38–43 mm in diameter after 7 d at 25 ° C in darkness, with a growth rate of 5.4–6.1 mm / day, undulate at edge, grey white to black in obverse and reverse.

Additional specimen examined.

CHINA • Yunnan Province, Yuxi City, Bailongtan Park , on diseased leaves of Clematis vitalba L., 12 May 2024, M. Y. Zhang ( HSAUP 8222–3 ), living culture SAUCC 8222–3 .

Notes.

Two isolates from leaf spots of Clematis vitalba phylogenetically clustered into a well-supported clade (1.00 / 100), which is closely related to P. concentrica ( CPC 18842 ) and P. kerriae ( MAFF 240047 ). However, P. clematidea differs from P. concentrica by 55 nucleotides (9 / 513 in ITS, 4 / 743 in LSU, 17 / 235 in tef 1, 18 / 220 in act, and 7 / 615 in gpdh) and from P. kerriae ( LSU and gpdh sequences are available) by 37 nucleotides (9 / 572 in ITS, 9 / 242 in tef 1, and 19 / 227 in act). In morphology, they are distinguished by different hosts ( Clematis vitalba vs. Hedera sp. vs. Kerria japonica ) and smaller conidia in P. clematidea than P. concentrica and P. kerriae (8–11.5 × 6–10 (5.5–7.5) 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 clematidea sp. nov.

Figures

Figure 6. Phyllosticta clematidea (CGMCC 3.28671) a diseased leaf of Clematis vitalba b, c colonies (left-above, right-reverse) after 7 d on PDA d conidiomata e, f conidiogenous cells with conidia g, h conidia. Scale bars: 10 μm (e – h).