Diaporthales » Diaporthaceae » Diaporthe

Diaporthe rosae

Diaporthe rosae Samarakoon & K.D. Hyde, sp. nov. Wanasinghe et al., Fungal Diversity: 10.1007/s13225-018-0395-7, [185] (2018) 

Index Fungorum number: IF554072            Facesoffungi number: FoF 03922

 

Saprobic on dead pedicel of Rosa sp. Sexual morph: Not observed. Asexual morph: Conidiomata: light to dark brown, scattered, ellipsoidal patches on the host surface 95–160 lm ([1]x = 123.9 lm, n = 22) long, 35–75 lm ([1]x = 54.9 lm, n = 10) high, 80–140 lm ([1]x = 110.9 lm, n = 10) diam at base, pycnidial, pyriform, initially immersed, erumpent at maturity, globose to pyriform, reddish brown, coriaceous, with elongate neck. Conidiomatal wall: 3–9 lm ([1]x = 5.8 lm, n = 22) wide, parenchymatous, consisting of 4–5 layers of pale brown, thick-walled cells of textura angularis. Conidiophores: reduced to conidiogenous cells, straight, branched, 2–3-cells high, hyaline, smooth. Conidiophores: 10–19 9 1.9– 3.3 lm ([1]x = 15 9 2.6 lm, n = 20), septate, branched, sometimes reduced to conidiogenous cells, hyaline, smooth. Alpha conidiogenous cells: 13 9 1–2.5 lm ([1]x = 9.9 9 2 lm, n = 25), phialidic, ampulliform, slightly tapering towards the apex with periclinal thickening, with a flared collarette. Hamathecium aparaphysate. Alpha conidia 5.5–7.5 9 2–3 lm ([1]x = 6.5 9 2.5 lm, n = 30), L/W ratio 2.6, enteroblstic, aseptate, hyaline, smooth, ovate to ellipsoidal, base subtruncate, often biguttulate. Beta conidiogenouc cells: 7.7–15 9 1.2–2.3 lm ([1]x = 12.5 9 1.9 lm, n = 10), phialidic, ampulliform, slightly tapering towards the apex with periclinal thickening, with a flared collarette. Beta conidia: not often found, 12.5–18 9 1–2 lm ([1]x = 14.6 9 1.4 lm, n = 10), L/W ratio 10.4, fusiform to hooked, aseptate, hyaline, smooth, base sub-truncate. Conidiomata: black, multilocular, scattered or aggregated produced on PDA after 6 weeks. Alpha conidia: not observed. Beta conidia: 12.6–21.1 9 0.7–1.2 lm ([1]x = 17.5 9 1 lm, n = 20), L/W ratio 17.8, fusiform to hooked, aseptate, hyaline, smooth, base sub truncate.

 

Culture characteristics: colonies on PDA, reaching 40–43 mm diam. after 2 weeks at 25 °C, fast growing, entire, flat, circular, white with radially arranged minute mycelium clots later becoming pale yellow, reverse: whitish, azonate. Odour not pronounced.

 

Material examined: THAILAND, Chiang Rai Province, Chiang Rai 57100, dead pedicel of Rosa sp. (Rosaceae), 3 May 2017, Milan C. Samarakoon, SAMC001, (MFLU 17 1550), ex-type living cultures MFLUCC 17 2658.

 

GenBank numbers: ITS: MG828894, LSU: MG829093,CaM: MG829273, BTUB: MG843878.

 

Notes: Combined multi-gene analysis shows that Diaporthe rosae clusters is basal to D. miriciae, D. passifloricola and D. ueckerae with 83% bootstrap in the ML analyses. ITS of D. rosae is 98% similar to D. miriciae, D. passifloricola and D. ueckerae and 95% similar to D. thumbergiicola. Globular conidiomata on PDA, comparatively small conidiogenous cells, conidiophores and beta conidia of Diaporthe rosae differ from D. miriciae and D. passifloricola (Thompson et al. 2015). The phylogenetically closely related species are reported from the host genera Camellia, Cucumis, Glycine, Helianthus, Passiflora and Vigna (Udayanga et al. 2015; Gao et al. 2016). Diaporthe rudis is the only species reported from Rosa canina (Rosaceae), which is phylogenetically and morphologically distinct to Diaporthe rosae and described as a new species, isolated from dead pedicel of potted Rosa sp.