Cytospora hippophaopsis R. Ma & G. F. Cai sp. nov.

Fig. 3

Etymology.

Referring to its morphological similarity to C. hippophaës.

Descriptions.

Ascostromata erumpent through the surface of bark. Disc black and circular with 6–16 ostioles per disc, ostiole black and circular, 54.5–103 µm (av. = 78.8 µm, n = 30) diam. Perithecium globular, 180.5–395 µm (av. = 285.1 µm, n = 30) diam. Asci clavate to elongate obovoid, 59.5–87 × 8–12.5 µm (av. = 73.6 × 9.9 µm, n = 30), eight-spored. Ascospores biseriate, elongate-allantoid, hyaline thin-walled and smooth-walled, 13–22.5 × 3.5–5.5 µm (av. = 18.4 × 4.4 µm, n = 50).

Cultural characteristics.

Colonies on PDA initially white, covering the petri dish in 7 d, becoming brown after 14 d. Ascomata formed after 16 d, white at the early stage, becoming black later.

Material examined.

China • Xinjiang Uygur Autonomous, Ili Autonomous Prefecture, Gongliu County, KurdinNing, Xiaomohe, 43°11'44.15"N, 82°43'41.66"E, 1288 m asl, on dead and dying branches of Malus sieversii, Rong Ma, 4 Aug 2016, holotype XJAU- 1378, living cultures XJAU 1378 = CGMCC 3.18997 (ITS: PP 965505, act: PP 957863, rpb 2: PP 957870, tef 1: PP 957877, tub 2: PP 957884); ibid. XJAU 1379 (ITS: PP 965506, act: PP 957864, rpb 2: PP 957871, tef 1: PP 957878, tub 2: PP 957885).

Notes.

Two isolates (XJAU 1378 and XJAU 1379) from the present study formed a distinct clade in the genus Cytospora (Fig. 2), which represents a new species named C. hippophaopsis. Cytospora hippophaopsis is morphologically similar to C. hippophaës from Hippophaë rhamnoides but differs in larger asci (59.5–87 × 8–12.5 µm vs. 38.6–44 × 5.9–7.8 µm) and ascospores (13–22.5 × 3.5–5.5 µm vs. 11.8–15 × 3–4.1 µm) (Fan et al. 2015).