Diaporthe chensiensis C.M. Tian & Q. Yang

Yang, Qin, Fan, Xin-Lei, Guarnaccia, Vladimiro & Tian, Cheng-Ming, 2018, High diversity of Diaporthe species associated with dieback diseases in China, with twelve new species described, MycoKeys 39, pp. 97-149 : 97

Diaporthe chensiensis C.M. Tian & Q. Yang sp. nov. Figure 9

Diagnosis.

Diaporthe chensiensis 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 Abies chensiensis , 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).

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 Abies chensiensis , 5 July 2017, Q. Yang, living culture CFCC 52568 (BJFC-S1481).

Notes.

Diaporthe chensiensis occurs in an independent clade (Fig. 1) and is phylogenetically distinct from D. vaccinii . Diaporhe chensiensis 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).