Polyplosphaeria nigrospora Kular. & K.D. Hyde

Classification – Tetraplosphaeriaceae, Pleosporales, Dothideomycetes, Ascomycota

Index Fungorum number – IF900418; Facesoffungi number – FoF 14173

Other useful webpages – outlineoffungi.org; fungalgenera.org; Dothideomycetes.org

Etymology – based on the black conidia.

Holotype – MHZU 22-0136

Description – Saprobic on dead stem of unidentified plant. Sexual morph: undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate solitary, scattered, as black spots. Hyphae superfcially spreading over the substrate, dark brown. Conidiophores reduced to conidiogenous cells. Conidiogenous cells micronematous, monoblastic, forming directly on creeping hyphae, holoblastic, integrated, terminal, determinate, connected to base of conidia, with guttules, hyaline. Conidia 60–70 × 45–65 µm (av. 68×57 µm, n = 20), globose to subglobose, pyriform or irregular, solitary, black, verrucose at base, with unbranched, brown setose appendages at base and almost hyaline at apex, setose appendages on surface in two forms; long appendages 40–65 × 3–4 µm (av. 55×3.6 µm, n = 10), thick-walled, 4-septate, arising from apical part of conidia; short appendages 30–50 × 3.5–5 µm (av. 40 × 4 µm, n = 10), aseptate, thin-walled, arising eccentrically from conidial base.

Culture characteristics – Colonies on PDA reaching 4 cm diam. after 14 days in dark at 25 °C, irregular, fat, wavy margin and zonation with bluish brown, inner zone comprises white aerial, mycelial clots; outer zone comprises pale brown, filiform hyphae forming wings-like pattern; reverse black with brown margin, sporulate after 14 days.

Material examined – China, Guangdong Province, Guangzhou City, Nansha District, Huangshan Lu Forest Park (22°78′74.2″ N 113°58.4′21″ E), dead stem of unidentified plant, 18 July 2021, N.D. Kularathnage, NDK 13–2 (MHZU 22-0136, holotype), ex-type cultures ZHKUCC 22-0132, ZHKUCC 22-0134.

GenBank accession numbers – ITS: OR164935, OR164936; LSU: OR164963, OR164964.

Notes – See Senanayake et al. (2023).

Polyplosphaeria nigrospora (MHZU 22-0136, holotype). a Colonies on substrate. b–g Conidia. h Surface view of colony on PDA. i Reverse view of colony on PDA. Scale bars: b–g = 50 µm.

Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, SSU and tef1-α sequence data for Polyplosphaeria nigrospora. Bootstrap support values for maximum likelihood equal to or greater than 50% and Bayesian posterior probabilities from Bayesian inference analysis equal to or greater than 0.90 are given at each node (ML/BYPP). The tree is rooted to Muritestudina chiangraiensis (MFLUCC 17-2551). Ex-type strains are in bold. The new isolates from South China region are indicated in blue.