Diaporthe alangii 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 alangii C.M. Tian & Q. Yang sp. nov. Figure 4

Diagnosis.

Diaporthe alangii can be distinguished from the phylogenetically closely related species D. tectonae and D. tulliensis by the size of conidiophores and alpha conidia.

Holotype.

CHINA. Zhejiang Province: Tianmu Mountain, on symptomatic branches of Alangium kurzii , 19 Apr. 2017, Q. Yang (holotype: BJFC-S1468; ex-type culture: CFCC 52556).

Etymology.

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

Description.

Conidiomata pycnidial, immersed in bark, scattered, erumpent through the bark surface, discoid, with a solitary undivided locule. Ectostromatic disc black, one ostiole per disc, 135-330 μm diam. Locule circular, undivided, 290-445 μm diam. Conidiophores 6-12 × 1.4-2 μm, cylindrical, hyaline, phiailidic, unbranched, straight. Alpha conidia 6.5-8 × 2 μm (av. = 7 × 2 μm, n = 30), aseptate, hyaline, ellipsoidal, biguttulate, mostly with one end obtuse and the other acute, occasionally submedian constriction. Beta conidia not observed.

Culture characters.

Cultures incubated on PDA at 25 °C in darkness. Colony initially white, producing beige pigment after 7-10 d. The colony is flat, felty with a thick texture at the centre and marginal area, with thin texture in the middle, lacking aerial mycelium, conidiomata absent.

Additional specimens examined.

CHINA. Zhejiang Province: Tianmu Mountain, on symptomatic branches of Alangium kurzii , 19 Apr. 2017, Q. Yang, living culture CFCC 52557 (BJFC-S1469); ibid. living culture CFCC 52558 (BJFC-S1470); ibid. living culture CFCC 52559 (BJFC-S1471).

Notes.

Four isolates clustered in a clade distinct from its closest phylogenetic neighbour, D. tectonae and D. tulliensis . Diaporthe alangii can be distinguished from D. tectonae in cal, tef1 and tub2 loci (6/458 in cal, 4/308 in tef1 and 11/407 in tub2); from D. tulliensis in ITS, tef1 and tub2 loci (6/462 in ITS, 8/308 in tef1 and 10/701 in tub2). Morphologically, D. alangii differs from D. tectonae in shorter conidiophores (6-12 vs. 11-18 μm) and longer alpha conidia (6.5-8 vs. 5.5-6 μm); from D. tulliensis in shorter conidiophores (6-12 vs. 15-20 μm) ( Crous et al. 2015, Doilom et al. 2017).