Diaporthe albosinensis 2020

Diaporthe albosinensis C.M. Tian & Q. Yang, sp. nov. 2020

MycoBank No: 829518

Holotype: China. Shaanxi Province: Ningshan County, Huoditang Forest Farm, 33°28'25"N, 108°29'39"E, on branches of Betula albosinensis, 10 July 2018, N. Jiang (holotype BJFC-S1670; ex-type living culture: CFCC 53066; living culture: CFCC 53067).

Morphological description

Conidiomata pycnidial, conical, immersed in bark, solitary to aggregated, erumpent through the bark surface, with a solitary undivided locule. Ectostromatic disc yellowish to brown, one ostiole per disc. Ostiole medium black, up to the level of disc. Locule undivided, (280–)290–375(–380) μm diam. Conidiophores (6–)8.5–13(–14.5) × (1.5–)2–2.5 μm, hyaline, cylindrical, smooth, phialidic, unbranched, straight or slightly curved. Alpha conidia hyaline, aseptate, fusiform, 0–1-guttulate, (7–)8–10(–11) × 2.5–3 μm. Beta conidia hyaline, aseptate, filiform, straight or slightly curved, eguttulate, base subtruncate, tapering towards one apex, (24–)25.5–30(–32) × 1–1.5 μm.Culture characters. Cultures incubated on PDA at 25 °C in the dark. Colony originally flat with white felted aerial mycelium, becoming light brown due to pigment formation, conidiomata irregularly distributed over agar surface, with yellowish conidial drops exuding from the ostioles.

Habitat: on branches of Betula albosinensis

Distribution: China

GenBank Accession: ITS MK432659，MK432660; cal MK442979，MK442980 ; his3 MK443004，MK443005; tef1 MK578133，MK578134；tub2 MK578059，MK578060

Notes: Two isolates, representing D. albosinensis, are retrieved in a well-supported clade (ML BS/BPP=100/1) and appear most closely related to D. fraxinicola (Fig. 1). Diaporthe albosinensis can be distinguished from D. fraxinicola, based on tef1 and tub2 loci (3/335 in tef1 and 19/429 in tub2). Morphologically, D. albosinensis differs from D. fraxinicola in having shorter conidiophores (8.5–13 vs. 10.5–17.5 μm) and longer beta conidia (25.5–30 vs. 19–29.5 μm) (Yang et al. 2018).

Reference: Yang Q, Jiang N, Tian C-M (2020) Three new Diaporthe species from Shaanxi Province, China.

Diaporthe albosinensis on Betula albosinensis (BJFC-S1670). A Habit of conidiomata in wood B transverse section of conidiomata C longitudinal section through conidiomata D conidiogenous cells attached with beta conidia e conidiogenous cells attached with alpha conidia F beta conidia. Scale bars: 200 μm (B–C); 20 μm (D, F); 10 μm (e).