Paraphomopsis obscurans (Ellis & Everh.) Udayanga & Castl. comb. nov. Fig. 2.

MycoBank number: MB 835530; Index Fungorum number: IF 835530; Facesoffungi number: FoF;

Basionym: Phoma obscurans Ellis & Everh., Proc. Acad. Nat. Sci. Phil. 46: 357. 1894.

Sphaeropsis obscurans (Ellis & Everh.) Kuntze, Revis. gen. pl. (Leipzig) 3(2): 1–576. 1898.

Phyllosticta obscurans (Ellis & Everh.) Tassi, Bulletin Labor. Orto Bot. de R. Univ. Siena 5: 13. 1902.

Dendrophoma obscurans (Ellis & Everh.) H.W. Anderson, University of Illinois Agricultural Experiment Station Bull. 229: 135. 1920.

Phomopsis obscurans (Ellis & Everh.) B. Sutton, Trans. Br. Mycol. Soc. 48(4): 615. 1965.

= Sphaeronaemella fragariae F. Stevens & Peterson, Phytopathology 6: 258. 1916.

Microascospora fragariae (F. Stevens & Peterson) Senan., Maharachch. & K.D. Hyde, Stud. Mycol. 86: 279. 2017.

Type: USA. WEST VIRGINIA: Fayette Co., on leaves of Fragaria sp., 08 July 1894, Nutall LW (1600 (7620) (J.B. Ellis 554)), (Lectotype designated here BPI 521547; MBT393834); ibid. (Iso-lectotype designated here, BPI 357247; MBT 393835); USA. MARYLAND: Beltsville Agriculture Research Center, Beltsville, on leaves of Fragaria × ananassa, 21 May 2015, Udayanga D. DS020, (Epitype designated here, BPI 919201; MBT 393833, ex- epitype culture M1262 = CBS 143829). GenBank: ITS = MT378347;   LSU = MT378361;    TEF1 = MT383096; RPB2 = MT383077.

Description: Pycnidia on alfalfa stems on WA: globose, ostiolate, scattered over the substrate, 40–55 μm diam, embedded in tissue, erumpent at maturity, with a slightly elongated, black neck 60–100 μm high, wider towards the apex at maturity, often with a yellowish, conidial cirrus extruding from ostiole; walls parenchymatous, consisting of 3–4 layers of medium brown textura angularis. Conidiophores hyaline, smooth, branched, ampulliform, long, slender, wider at the base, 9–12 μm long and wide. Conidiogenous cells phialidic, cylindrical, terminal, slightly tapering towards apex, 1.5–2.5 μm diam at the widest point. Collarette present and conspicuous. Paraphyses ab- sent. Alpha conidia 5–7 × 1.5–2.2 μm (avg. ± SD = 6 ± 0.5 × 2 ± 0.2, n = 30), abundant in culture and on alfalfa stems, aseptate, hyaline, smooth, ellipsoidal to fusiform, often biguttulate and rarely multiple guttules and confined to minute particles clumped towards the vertices of the spore, base subtruncate. Beta conidia unknown. Culture on PDA under artificial light at 25 °C for 1 wk., growth rate: 4.5 ± 0.2 mm/day (n = 3), white, sparse aerial mycelium, with pale olivaceous grey (120) pigmentation and abundant sporulation with aging, olivaceous grey (107) pigmentation developing in reverse.

Additional specimens examined: USA. MARYLAND: Beltsville Agriculture Research Center, Beltsville, on leaves of Fragaria × ananassa, 22 May 2015, Udayanga D. DS013 (BPI 919179), living culture M1259; ibid, 19 June 2015, Udayanga D. DS021, June 082015 DS134 (BPI 19204); ibid, DS016 (BPI 919180), living culture M1261; ibid, Greenhouses at Beltsville Agriculture Re- search Centre, Beltsville, on leaves of Fragaria × ananassa, 29 Sept. 2015, Udayanga D. GR002 (BPI 919182); ibid, Davis Mill Road, Germantown (Montgomery County), on leaves of Fragaria × ananassa ‘Darselect’, 24 June 2015, Butler B. DS053 (BPI 919185) living culture M1276; ibid, Davis Mill Road, Germantown (Montgomery County), on leaves of Fragaria × ananassa ‘Darselect’, 12 Oct. 2016, Butler B. DS090 (BPI 919192).

Geographic distribution: Australia (Cook and Dubé 1989; Shivas 1989; Cunnington 2003), Brazil (Mendes et al. 1998), Brunei Darussalam (Peregrine and Bin Ahmad 1982), Bulgaria (Bobev 2009), China (Jinping 2011; Shi et al. 2013), Egypt (Haggag 2009; Abd-El- Kareem et al. 2019), Malawi (Peregrine and  Siddiqi 1972), Myanmar  (Thaung  2008),  South  Africa  (Crous et al. 2000), Tonga (Dingley et al. 1981), USA: Florida, Maryland, North Carolina, Ohio, Oregon, Washington, West Virginia (Alfieri Jr et al. 1984; Cash 1953; Shaw 1973; Maas 1998; Farr and Rossman 2020).

Notes: Although the appearance of conidia is superficially similar to Phomopsis (Syn. Diaporthe), microscopic examination revealed that the shape and overall appearance of guttules are distinct from those in Diaporthe species. In general, conidia of Paraphomopsis obscurans are fusiform with minute guttules toward the end of the conidia, whereas most Diaporthe species bear ovate to clavate conidia with no or prominent biguttulate or multiguttulate conidia. Paraphomopsis obscurans can be distinguished from the closely related species Microascospora rubi and other genera in the family Melanconiellaceae based on its morphology and robust support of the multilocus phylogeny. Due to confusion of nomenclature and taxonomy, previous records of the pathogen from various geographic locations were linked to multiple names: Phoma obscurans, Sphaeronaemella fragariae and Phomopsis obscurans, or misidentified as Gnomonia fragariae, Gnomonia comari and Gnomoniop- sis fragariae. Therefore, the actual distribution of the fungus may be largely underestimated.

Fig. 2 Morphology of Paraphomopsis obscurans (BPI 919201, culture CBS 143829/M1262, isolate DS020). a Infected leaf of Fragaria × ananassa. b– d Leaf blight symptoms under stereo microscope. e,f Pycnidia on alfalfa stems on WA. g Pycnidia on PDA. h Conidiophores. i,j Conidia. k 7-d-old culture on PDA. l 7-d-old culture on MEA. m 7-d-old culture on V8A. Scale bars: a = 4 cm, b = 1.5 cm, c,d = 1 cm, e-g = 300 μm, h-j = 10 μm