Diaporthe rugulosa Y.Y. Chen, A.J. Dissanayake and Jian K. Liu sp. nov. (Figure c)

MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 12614;

Etymology: Refers to the wrinkles in the colony (reverse on PDA).

Holotype: GZAAS 19-1798

Saprobic on decaying leaf. Sexual morph: Not observed. Asexual morph: Conidiomata 200–300 μm diam., globose to irregular, erumpent at maturity. Peridium up to 60–80 μm diam., parenchymatous, consisting of 3–8 layers of medium brown textura angularis. Conidiophores 15–25 × 2–2.4 μm, cylindrical, hyaline, smooth, branched, ampulliform, straight to sinuous. Conidiogenous cells up to 0.5–1 μm, phialidic, cylindrical, terminal, with slight tapering towards apex. Paraphyses 15–30 × 1–2 μm, abundant among conidiophores. Alpha conidia (5–)7–8(–9) × 2–3.5 μm ( = 8 × 3, n = 30), aseptate, hyaline, smooth, ovate to ellipsoidal, biguttulate, base subtruncate. Beta conidia (18–)22–28(–30) × (2–)3–4(–4) μm ( = 24 × 3, n = 30), aseptate, hyaline, smooth, fusiform or hooked, base subtruncate.

Culture characteristics: Colonies covering entire PDA Petri dishes after 10 d at 25 °C, flat, with an entire edge, aerial mycelium forming concentric rings with cottony texture. Olivaceous-buff, isabelline to honey on reverse surface.

Material examined: China, Guizhou Province, DuShan county, saprobic on decaying leaf, May 2020, Y. Y. Chen (GZAAS 19-1798, holotype); ex-type living culture CGMCC = GZCC 19-0079; ibid, Xingyi city, saprobic on decaying woody host, May 2019, Y. Y. Chen (GZAAS 19-1844, paratype), living culture GZCC 19-1025; ibid., GZAAS 22-0029, living culture GZCC 22-0028; ibid., GZAAS 22-0024, living culture GZCC 22-0035; ibid., GZAAS 22-0037, living culture GZCC 22-0036; ibid., GZAAS 22-0053, living culture GZCC 22-0052.

Notes: The phylogenetic results showed that six isolates of Diaporthe rugulosa clustered closer to D. spinosa forming a distinct lineage (Figure 2) with maximum support (ML/MP/BI = 100/100/1.0). Diaporthe rugulosa can be distinguished from D. spinosa in the concatenated alignment by 30/512 in ITS, 6/413 in tef, 17/453 in tub, 34/506 in cal and 8/515 in his. Diaporthe rugulosa differs from D. spinosa in having concentric rings in the PDA media (Guo et al. 2020). As D. rugulosa has no reported sexual morph, we were unable to compare their morphology.

Figure c. Diaporthe rugulosa (GZAAS 19-1798, holotype). a, b Conidiomata on host surface. c Section of conidiomata. d Conidia attached to conidiophores. e Alpha conidia. f Alpha conidia stained in methylene blue. g Beta conidia. h 10 days old culture on PDA from above. i 10 days old culture on PDA from reverse. Scale bars: c = 100 μm; d–f = 20 μm, g = 5 μm.