Diaporthe caryae 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 caryae C.M. Tian & Q. Yang sp. nov. Figure 7

Diagnosis.

Diaporthe caryae differs from its closest phylogenetic neighbour, D. charlesworthii and D. sackstonii , in ITS, tef1 and tub2 loci based on the alignments deposited in TreeBASE.

Holotype.

CHINA. Jiangsu Province: Nanjing city, on symptomatic twigs of Carya illinoensis , 10 Nov. 2015, Q. Yang (holotype: BJFC-S1476; ex-type culture: CFCC 52563).

Etymology.

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

Description.

Conidiomata pycnidial, immersed in bark, scattered, slightly erumpent through the bark surface, nearly flat, discoid, with a solitary undivided locule. Ectostromatic disc brown to black, one ostiole per disc. Locule undivided, 310-325 μm diam. Conidiophores 7-11 × 1.4-2.2 μm, cylindrical, phialidic, unbranched, sometimes inflated. Alpha conidia hyaline, aseptate, ellipsoidal or fusiform, eguttulate, obtuse at both ends, 7-8.5 × 2.1-2.5 μm (av. = 8 × 2.3 μm, n = 30). Beta conidia hyaline, aseptate, filiform, straight or hamate, eguttulate, base subtruncate, tapering towards one apex, 15.5-34 × 1.1-1.4 µm (av. = 27.5 × 1.2 µm, n = 30).

Culture characters.

Cultures incubated on PDA at 25 °C in darkness. Colony at first flat with white felty mycelium, becoming black in the centre and black at the marginal area with age, conidiomata not observed.

Additional specimens examined.

CHINA. Jiangsu Province: Nanjing city, on symptomatic twigs of Carya illinoensis , 10 Nov. 2015, Q. Yang, living culture CFCC 52564 (BJFC-S1477).

Notes.

Two strains representing D. caryae cluster in a well-supported clade and appear closely related to D. charlesworthii and D. sackstonii . Diaporthe caryae can be distinguished based on ITS, tef1 and tub2 loci from D. charlesworthii (50/468 in ITS, 107/338 in tef1 and 90/707 in tub2); from D. sackstonii (4/440 in ITS, 13/340 in tef1 and 23/701 in tub2). Morphologically, D. caryae can be distinguished from D. charlesworthii by its shorter conidiophores (7-11 vs. 15-35 μm); from D. sackstonii by its longer alpha conidia (7-8.5 vs. 6-7 μm) ( Thompson et al. 2015).