Diagnosis.

Taxon classification

Fungi

Diaporthales

Diaporthaceae

Yang

Qin

Fan

Xin-Lei

Guarnaccia

Vladimiro

Tian

Cheng-Ming

High diversity of

Diaporthe

species associated with dieback diseases in China, with twelve new species described

MycoKeys179201820183997149

10.3897/mycokeys.39.26914

Diaporthe

chensiensis

MB824708

C.M. Tian & Q. Yang

sp. nov.

Figure 9

Diagnosis.

Diaporthechensiensis differs from its closest phylogenetic neighbour, D.vaccinii, in ITS, cal, his3 and tef1 loci based on the alignments deposited in TreeBASE.

Holotype.

CHINA. Shaanxi Province: Ningshan County, Huoditang forest farm, on symptomatic twigs of Abieschensiensis, 5 July 2017, Q. Yang (holotype: BJFC-S1480; ex-type culture: CFCC 52567).

Etymology.

Named after the host species on which it was collected, chensiensis.

Description.

Conidiomata pycnidial, immersed in bark, scattered, slightly erumpent through the bark surface, discoid, with a single locule. Ectostromatic disc white to brown, one ostiole per disc, 200–325 μm diam. Locule undivided, 385–540 μm diam. Conidiophores 8.5–13 × 2–3 μm, cylindrical, hyaline, phiailidic, unbranched, straight or slightly curved, tapering towards the apex. Alpha conidia hyaline, aseptate, smooth, ellipsoidal, biguttulate, rounded at both ends, 6.5–11 × 2–2.2 μm (av. = 8.5 × 2.1 μm, n = 30). Beta conidia present on the host, hyaline, eguttulate, smooth, filiform, hamate, 21–28.5 × 0.8–1.1 μm (av. = 25 × 1 μm, n = 30).

Figure 9.

Diaporthechensiensis (CFCC 52567) A–B Habit of conidiomata on branches C Transverse section of conidioma D Longitudinal section of conidioma E Alpha conidia F Beta conidia G Conidiophores H Culture on PDA and conidiomata. Scale bars: 500 μm (B), 200 μm (C–D), 10 μm (E), 20 μm (F).

Culture characters.

Cultures incubated on PDA at 25 °C in darkness. Colony originally flat with white felted aerial mycelium, becoming light brown mycelium due to pigment formation, conidiomata irregularly distributed over agar surface, with yellowish conidial drops exuding from the ostioles.

Additional specimens examined.

CHINA. Shaanxi Province: Ningshan County, Huoditang forest farm, on symptomatic twigs of Abieschensiensis, 5 July 2017, Q. Yang, living culture CFCC 52568 (BJFC-S1481).

Notes.

Diaporthechensiensis occurs in an independent clade (Fig. 1) and is phylogenetically distinct from D.vaccinii. Diaporhechensiensis can be distinguished from D.vaccinii by 57 nucleotides in concatenated alignment, in which 14 were distinct in the ITS region, 13 in the cal region, 10 in the his3 region, 15 in the tef1 region and 15 in the tub2 region. Although this species belongs to the D.eres complex, it is, however, distinct from the known species within the complex (Fig. 2).

Figure 1.

Phylogram of Diaporthe from a maximum likelihood analysis based on combined ITS, cal, his3, tef1 and tub2. Values above the branches indicate maximum likelihood bootstrap (left, ML BP ≥ 50%) and bayesian probabilities (right, BI PP ≥ 0.70). The tree is rooted with Diaporthellacorylina. Strains in the current study are in blue.

Figure 2.

Phylogram of Diaportheeres complex based on combined cal, tef1 and tub2. Values above the branches indicate maximum parsimony bootstrap (left, MP BP ≥ 50%) and maximum likelihood bootstrap (right, ML BP ≥ 50%). Values below branches represent posterior probabilities (BI PP ≥ 0.70) from Bayesian inference. The tree is rooted with Diaporthecitri. Strains in the current study are in blue. The ex-type/ex-epitype culture is in bold.