Diaporthe padina 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 padina C.M. Tian & Q. Yang sp. nov. Figure 15

Diagnosis.

Diaporthe padina can be distinguished from the phylogenetically closely related species D. betulae in smaller conidiomata and alpha conidia.

Holotype.

CHINA. Heilongjiang Province: Liangshui Nature Reserve, on symptomatic twigs of Padus racemosa , 31 July 2016, Q. Yang (holotype: BJFC-S1501; ex-type culture: CFCC 52590).

Etymology.

Named after the host genus on which it was collected, Padus .

Description.

Conidiomata pycnidial, immersed in bark, scattered, slightly erumpent through the bark surface, discoid, with a single locule. Ectostromatic disc light brown, one ostiole per disc, 330-520 μm diam. Locule circular, undivided, 250-550 μm diam. Conidiophores 5.5-12.5 × 1-1.5 μm, hyaline, unbranched, cylindrical, straight or slightly curved. Alpha conidia hyaline, aseptate, ellipsoidal to fusiform, eguttulate, 7-8 × 1.5-2 μm (av. = 7.5 × 1.8 μm, n = 30). Beta conidia hyaline, filiform, straight or hamate, eguttulate, aseptate, base truncate, 21-24 × 1 µm (av. = 22 × 1 µm, n = 30).

Culture characters.

Cultures incubated on PDA at 25 °C in darkness. Colony originally flat with white aerial mycelium, becoming grey to brown in the centre, with pale grey, felted, valviform mycelium at the marginal area and aggregated conidiomata at maturity.

Additional material examined.

CHINA. Heilongjiang Province: Liangshui Nature Reserve, on symptomatic twigs of Padus racemosa , 31 July 2016, Q. Yang, living culture CFCC 52591 (BJFC-S1502).

Notes.

Four strains representing D. padina cluster in a well-supported clade and appear closely related to D. betulae . This species is phylogenetically closely related to, but clearly differentiated from, D. betulae by 40 different unique fixed alleles in ITS, cal, his3, tef1 and tub2 loci (4, 7, 10, 13 and 6 respectively) based on the alignments deposited in TreeBASE. Morphologically, D. padina differs from D. betulae in smaller conidiomata and alpha conidia (250-550 vs. 600-1250 μm in conidiomata; 7-8 × 1.5-2 vs. 8.5-11 × 3-4 μm in alpha conidia) ( Du et al. 2016).