Diaporthe verniciicola C.M. Tian & Q. Yang, 2021

Yang, Qin, Jiang, Ning & Tian, Cheng-Ming, 2021, New species and records of Diaporthe from Jiangxi Province, China, MycoKeys 77, pp. 41-64 : 41

Diaporthe verniciicola C.M. Tian & Q. Yang sp. nov. Figure 8

Diagnosis.

Distinguished from the phylogenetically closely-related species D. rostrata in having smaller alpha conidia; and from D. juglandicola in having wider alpha conidia.

Etymology.

Named after the host genus Vernicia on which the fungus was isolated.

Description.

Conidiomata pycnidial, 825-1050 × 445-500 μm diam., solitary and with single necks erumpent through host bark. Tissue around neck is conical. Locule circular, undivided, 400-665 μm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells unbranched, straight or sinuous, 14.5-21.5 × 1-1.5 μm. Alpha conidia hyaline, aseptate, ellipsoidal to fusiform, with 1-2-guttulate, 7-8.5 × 3-3.5 μm. Beta conidia not observed.

Culture characters.

Colony white to yellowish, with dense and felted mycelium in the centre, lacking aerial mycelium, conidiomata absent.

Specimens examined.

China. Jiangxi Province: Ganzhou City, on branches of Vernicia montana , 24°40'51"N, 115°34'52"E, 12 May 2018, Q. Yang, Y. Liu & Y.M. Liang (holotype BJFC-S1622; ex-type culture: CFCC 53109); 24°40'52"N, 115°34'50"E, 12 May 2018, Q. Yang, Y. Liu & Y.M. Liang (BJFC-S1623; living culture: CFCC 53110); 24°45'14"N, 115°34'00"E, 12 May 2018, Q. Yang, Y. Liu & Y.M. Liang (BJFC-S1624; living culture: CFCC 53111); 25°44'15"N, 114°59'32"E, 15 May 2018, Q. Yang, Y. Liu & Y.M. Liang (BJFC-S1624; living culture: CFCC 53112).

Notes.

Two isolates of D. verniciicola clustered in a well-supported clade (ML/BI = 100/1) and appeared closely related to D. rostrata and D. juglandicola (Fig. 1 ). Morphologically, D. verniciicola is similar to D. rostrata characterised by conidiomata with single necks erumpent through the host bark. However, the new taxon can be distinguished from D. rostrata in having smaller alpha conidia (7-8.5 × 3-3.5 vs. 8.5-11.5 × 4-5 μm) ( Fan et al. 2015) and D. verniciicola differs from D. juglandicola in having wider alpha conidia (3-3.5 vs. 2.5-3 μm) ( Yang et al. 2017b). This is the first discovery of a Diaporthe species isolated from infected branches or twigs on Vernicia montana and was confirmed as a new species, based on phylogeny and morphology.

Figures

Figure 1. Phylogram of Diaporthe from a Maximum Likelihood analysis based on combined ITS, cal, his 3, tef 1 and tub 2. Values above the branches indicate Maximum Likelihood bootstrap (left, ML BP ≥ 50 %) and Bayesian probabilities (right, BI PP ≥ 0.90). The tree is rooted with Diaporthella corylina. Strains in current study are in blue font and the ex-type cultures are in bold font.

Figure 8. Diaporthe verniciicola on Vernicia montana (BJFC-S 1622) a, b habit of conidiomata on twig c transverse section through conidiomata d longitudinal section through conidiomata e alpha conidia f conidiophores g culture on PDA (30 d). Scale bars: 500 μm (b); 200 μm (c); 10 μm (e, f).