Cytospora pinea A.L. Jia & X.L. Fan sp. nov.

Fig. 8

Etymology.

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

Typification.

China, Beijing City, Fengtai Distinct, Lotus Pond Park, 39°53'27.64"N, 116°18'49.21"E, from branches of Pinus bungeanae, 9 Feb 2023, X.L. Fan (holotype BJFC CF20230413, ex-holotype living culture CFCC 59521; 39°53'27.21"N, 116°18'49.56"E, from branches of Pinus bungeanae, 9 Feb 2023, X.L. Fan (paratype BJFC CF20230415, ex-paratype living culture CFCC 59523).

Description.

Sexual morph: not observed. Asexual morph: Conidiomata pycnidial, immersed in bark, scattered, nearly flat, slightly erumpent through the bark surface in a large area, with multiple locules. Conceptacle absent. Ectostromatic disc light brown to black, inconspicuous, circular to ovoid, with one ostiole per disc. Ostiole black, conspicuous, 150-200 μm diam. Locules numerous, irregular, subdivided frequently by invaginations with common walls, 980-1130 µm diam. Conidiophores borne along the locules, hyaline, branched at the base, in the middle or unbranched, thin-walled, 15-22 × 1.5-2.5 μm (av. = 18 ± 2.3 × 2 ± 0.3 μm, n = 30), embedded in a gelatinous layer. Conidiogenous cells enteroblastic, phialidic, sub-cylindrical, 3-7.5(-8) × 1-2 μm (av. = 4.5 ± 1.4 × 1.6 ± 0.3 μm, n = 50), tapering towards apices; arranged in rosettes. Conidia hyaline, allantoid, eguttulate, smooth, aseptate, thin-walled, 3.5-5 × 1-2 μm (av. = 4.3 ± 0.5 × 1.4 ± 0.2 μm, n = 50).

Culture characteristics.

Cultures on PDA are initially white, growing slowly up to 2 cm in diam. after 3 d and becoming yellowish after 7-10 d. Colonies thin with a uniform texture, lacking aerial mycelium, entirely covering the 6 cm Petri dish after 14 d, with a regular edge. After 30 d, pycnidia irregularly distributed on culture surface.

Additional materials examined.

China, Beijing City, Fengtai Distinct, Lotus Pond Park, 39°53'26.87"N, 116°18'43.46"E, from branches of Pinus bungeanae, 9 Feb 2023, X.L. Fan (BJFC CF20230414, living culture CFCC 59522; BJFC CF20230416, living culture CFCC 59524) .

Notes.

Cytospora pinea is associated with canker disease of Pinus bungeanae in China. Cytospora pinea is close to C. bungeanae in the phylogenetic diagram (Fig. 2) and was isolated from the same host species Pinus bungeanae (Fan et al. 2020). It can be distinguished from C. bungeanae by smaller conidiophores (3-7.5(-8) × 1-2 vs. 15-27(-30) × 1.5-2 μm in C. bungeanae) and smaller locules (980-1130 vs. (1150-)1220-1480(-1600) μm in C. bungeanae). Furthermore, Cytospora pinea has a black conspicuous ostiole per disc, whereas the ostiole of C. bungeanae is inconspicuous. Phylogenetically, there are differences of 76/344 in the act region and 7/811 in the tef1-α gene with gaps.