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

Yang, Qin, Jiang, Ning & Tian, Cheng-Ming, 2020, Three new Diaporthe species from Shaanxi Province, China, MycoKeys 67, pp. 1-18 : 1

Diaporthe shaanxiensis C.M. Tian & Q. Yang sp. nov. Fig. 4

Diagnosis.

Distinguished from D. aquatica and D. incompleta in having longer beta conidia.

Etymology.

Named after Province Shaanxi, where the holotype was collected.

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.

Specimens examined.

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).

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).

Figures

Figure 1. Phylogram of Diaporthe resulting from a maximum likelihood analysis based on combined ITS, cal, his 3, tef 1 and tub 2. Numbers above the branches indicate ML bootstraps (left, ML BS ≥ 50 %) and Bayesian Posterior Probabilities (right, BPP ≥ 0.90). The tree is rooted with Diaporthella corylina. Isolates in current study are in blue. " - " indicates ML BS <50 % or BI PP <0.90.

Figure 4. Diaporthe shaanxiensis on liana (BJFC-S 1674). 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).