Dendrostoma shaanxiense C.M. Tian & N. Jiang

Jiang, Ning, Fan, Xin-Lei, Crous, Pedro W. & Tian, Cheng-Ming, 2019, Species of Dendrostoma (Erythrogloeaceae, Diaporthales) associated with chestnut and oak canker diseases in China, MycoKeys 48, pp. 67-96 : 85-86

Dendrostoma shaanxiense C.M. Tian & N. Jiang sp. nov. Figure 11

Diagnosis.

Dendrostoma shaanxiense is distinguished from the closely related species D. castaneae by smaller l/w ratio and from D. castaneicola by its narrower conidia.

Holotype.

CHINA. Shaanxi Province: Ankang City, Xiangxidong Park, 32°40'32"N, 109°18'57"E, 1079 m a.s.l., on branches of Castanea mollissima , 1 Jul. 2017, N. Jiang (holotype: BJFC-S1549; ex-type culture: CFCC 52741).

Etymology.

Shaanxiense, referring to the Shaanxi Province in China.

Description.

Sexual morph not observed. Asexual morph: Conidiomata pycnidial, conical to pulvinate, occurring separately, dark orange, semi-immersed in bark, 350-650 μm high, 1050-1400 μm diam.; wall of several layers of bright yellow textura angularis; central column beneath the disc conical, bright yellow. Conidiophores reduced to conidiogenous cells. Conidiogenous cells lining the inner walls of the cavity, hyaline, smooth, subcylindrical to ampulliform, 5-11 × 2.5-3.5 μm. Conidia hyaline, aseptate, smooth, multiguttulate, thin-walled, ellipsoid to fusoid, straight to curved, (8.6 –)9.5–11.1(– 11.7) × (2.3 –)2.5–3.1(– 3.4) μm, l/w = (2.8 –)3.3–4.2(– 4.9) (n = 50).

Culture characters.

On PDA, cultures are initially white, turning purple after 2 weeks on PDA. The colonies are flat with irregular edge; texture uniform, producing concentric circles within 1 month at 25 °C in the dark.

Additional specimen examined.

Shaanxi Province: Ankang City, Xiangxidong Park, 32°40'32"N, 109°18'57"E, 1079 m a.s.l., on branches of Castanea mollissima , 1 Jul. 2017, N. Jiang, CFCC 52742 (BJFC-S1550).

Notes.

Dendrostoma shaanxiense , D. castaneae and D. castaneicola are phylogenetically closely related species occurring on the same host, Castanea mollissima (Fig. 2). However, Dendrostoma shaanxiense has conidia with a smaller l/w ratio than D. castaneae (3.3-4.2 in D. shaanxiense vs. 4.2-5.2 in D. castaneae ) and has narrower conidia than D. castaneicola (2.5-3.1 μm diam. in D. shaanxiense vs. 3.2-3.8 μm diam. in D. castaneicola ).