Diaporthe shaanxiensis 2020

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

MycoBank No: 829527

Holotype: CHINA. Shaanxi Province: Ningshan County, Huoditang Forest Farm, 33°28'25"N, 108°29'39"E, on branch of liana, 10 July 2018, N. Jiang (holotype BJFC-S1674; ex-type living culture: CFCC 53106); 33°28'24"N, 108°29'38"E, on branch of liana, 10 July 2018, N. Jiang (Paratype BJFC-S1675; living culture: CFCC 53107).

Morphological description

Conidiomata pycnidial, immersed in bark, scattered, erumpent through the bark surface, discoid, with a solitary undivided locule. Ectostromatic disc yellowish to pale brown, one ostiole per disc, usually conspicuous, (485–)500–687(–695) μm diam. Locule circular, undivided, (500–)526–765(–792) μm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, cylindrical, unbranched, slightly curved, tapering towards the apex, (12.5–)14.5–17(–18) × 1–1.5(– 2) μm. Alpha conidia not observed. Beta conidia hyaline, aseptate, filiform, straight to curved, eguttulate, (35.5–)37–47.5(–50) × 1 μm. Culture characters. Cultures incubated on PDA at 25 °C in the dark. Colony originally flat with white fluffy aerial mycelium, becoming pale brown with pigment, with visible solitary conidiomata at maturity.

Habitat: on branch of liana 

Distribution: China

GenBank Accession: ITS MK432654，MK432655; cal MK442976，MK442977 ; his3 MK443001，MK443002; tef1 MK578130，MK578131；tub2 NA，NA

Notes: In the combined tree, D. shaanxiensis is a distinct clade with maximum support and it appears to be most closely related to D. aquatica and D. incompleta (Fig. 1). Diaporthe shaanxiensis can be distinguished from D. aquatica by a 17 nt difference in the ITS region. For D. aquatica, only ITS sequences are available in NCBI GenBank (Hu et al. 2012). The new species can be distinguished from D. incompleta, based on ITS, cal, his3 and tef1 (24/454 in ITS, 14/443 in cal, 66/468 in his3 and 24/311 in tef1). Morphologically, D. shaanxiensis differs from both D. aquatica (37–47.5 vs. 9–12.5 μm) and D. incompleta (37–47.5 vs. 19–44 μm) in having longer beta conidia (Gao et al. 2016, 2017).

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

Diaporthe shaanxiensis on liana (BJFC-S1674). A, B Habit of conidiomata on twig C transverse section through conidiomata D longitudinal section through conidiomata e conidiogenous cells attached with beta conidia F beta conidia. Scale bars: 200 μm (B–D); 10 μm (e, F).