Curvularia cynodontis Lin Huang, Jia-Mei Zhao & D. W. Li, 2025

Zhao, Jia-Mei, Peng, Chuan-Xu, Zhang, Qiu-Yue, Li, De-Wei & Huang, Lin, 2025, Five novel species of Curvularia (Pleosporales, Pleosporaceae) isolated from turfgrasses, MycoKeys 125, pp. 279-305 : 279-305

Curvularia cynodontis Lin Huang, Jia-Mei Zhao & D. W. Li sp. nov.

Fig. 3

Holotype.

China • Jiangsu Province, Nanjing, Xuanwu District, Shinsemon Park , 32 ° 09 ' 12 " N, 118 ° 78 ' 31 " E, isolated from leaf blight of Cynodon dactylon , 22 June 2024. Holotype: CFCC 72724 is a living specimen being maintained via lyophilisation at the China Forestry Culture Collection Center ( CFCC). Ex-type ( SCM 16-22 ) is maintained at the Forest Pathology Laboratory, Nanjing Forestry University.

Etymology.

The name refers to the name of the host genus, Cynodon , from which the holotype was collected.

Description.

Asexual morph on PDA: Hyphae 2–5 μm wide, subhyaline to pale brown, thin- and smooth-walled, septate, branched. Conidiophores mononematous, semi- macronematous, septate, arising singly or frequently in groups, straight to slightly flexuous, mostly unbranched, rarely short-branched apically, smooth to verruculose, yellowish-brown to brown, (25 –) 45–121 (– 182) × 3–7 μm (mean ± SD = 83 ± 38 × 5 ± 1 μm). Conidiogenous cells mono- to polytretic, proliferating sympodially, integrated, terminal or intercalary, subcylindrical to irregularly swollen, brown to dark brown, with darkened scars, smooth, (5 –) 7–11 (– 15) × 3–5 μm (mean ± SD = 9 ± 2 × 4 ± 1 μm). Conidia 2–5 - euseptate, all septa are strongly thickened and swollen, straight, elliptical, smooth, (14 –) 19–27 (– 32) × (5 –) 6–8 μm (mean ± SD = 23 ± 4 × 7 ± 1 μm); germination mono- or bipolar. Hila 2–4 μm wide, conspicuous protuberant, thickened and darkened. Chlamydospores and microconidiation not observed. Sexual morph: Undetermined. Culture characteristics. Colonies on PDA reach 39 mm diam. after 5 days at 25 ° C in the dark. Round colony with regular margins, cottony appearance, fluffy aerial hyphae, grey in the central sporulating zone, white in the marginal aging zone, black in the centre of the reverse and white at the edges. On OA medium, the colonies’ diameter is up to 49 mm, the surface is smooth, the edge is neat and the front and reverse of the colony are black. The back is greyish-black in the centre and white on the edges. On CMA medium, the diameter is up to 49 mm and the colony morphology is similar to that on OA.

Additional materials examined.

(All isolated from leaf blight of Cynodon dactylon ). China • Jiangsu Province, Nanjing, Xuanwu District, Xuanwu Lake Park , 21 May 2024, Jia-Mei Zhao and Lin Huang, XW 6-23; Jianye District , Yuzui Wetland Park, 29 Aug 2024, Jia-Mei Zhao and Lin Huang, YZ 26-27 .

Notes.

Phylogenetically, Curvularia cynodontis forms a distinct, strongly supported lineage, placed in the same clade as C. beasleyi , C. nodosa and C. khuzestanica (Fig. 2 ). However, these species are readily distinguishable morphologically. Curvularia beasleyi , C. nodosa and C. khuzestanica show uniform width in basal and middle sections, but widen apically, resembling hyphae, whereas C. cynodontis maintains consistent conidiophores width distinct from hyphae ( Marin-Felix et al. 2017; Tan et al. 2018). Additionally, C. nodosa exhibits inconspicuous septate conidia, whereas C. cynodontis shows distinctly visible septa in all cells ( Marin-Felix et al. 2017). Curvularia nodosa and C. beasleyi exhibit longer conidiophores than C. cynodontis (70–230 μm vs. 45–121 μm in the former, up to 110 μm vs. 45–121 μm in the latter, Marin-Felix et al. (2017); Tan et al. (2018)). In addition, C. khuzestanica produces significantly shorter conidiophores than those of C. cynodontis (24–90 μm vs. 45–121 μm; Tan et al. (2018)).

Figures

Figure 2. Phylogenetic relationships of Curvularia strains isolated from turfgrasses and closely-related taxa of Curvularia, based on Maximum Likelihood analyses using concatenated ITS + GAPDH + tef 1 sequences. Numbers above the branches indicate ML bootstrap values (left, ML ≥ 50 %) and Bayesian posterior probabilities (right, BPP ≥ 0.90). T = Ex-type strain.

Figure 3. Curvularia cynodontis (SCM 16-22, type). A – C. Colony on PDA (A), OA (B) and CMA (C), respectively in 5 days after incubation at 25 ° C; D. Sporulation on PDA; E – J. Conidia, conidiogenous cells and conidiophores; K – L. Conidiophore; M. Conidia. Scale bars: 50 μm (D); 20 μm (H); 10 μm (E – G, I – M).