Didymella eriobotryae Thambug. & K.D. Hyde, 2018

Thambugala, Kasun M., Hyde, Kevin D., Zhang, Jin-Feng & Liu, Zuo-Yi, 2018, Didymella eriobotryae sp. nov. (Didymellaceae) and Arthrinium arundinis (Apiosporaceae) from fruit of Eriobotrya japonica (loquat) in China, Phytotaxa 382 (1), pp. 136-147 : 142-143

Didymella eriobotryae Thambug. & K.D. Hyde , sp. nov.

Index Fungorum number: IF 554287, Facesoffungi number: FoF04189, Fig. 4

Etymology: Named after the host genus from which it was collected, Eriobotrya

Holotype: MFLU 16–2599

Associated with loquat fruit ( Eriobotrya japonica (Thunb.) Lindl. ) forming black spots. Sexual morph Undetermined. Asexual morph Description from ex-type living culture (MFLUCC 16–0489). Conidiomata 130–260 μm high × 100– 240 μm diam. (x = 195 × 175 μm, n = 15), pycnidial, solitary or gregarious, scattered, semi-immersed to erumpent, or superficial, uniloculate, globose to subglobose, ostiolate, sometimes bearing dark brown to black setae. Conidiomatal wall 10–30 μm wide, comprising several layers of dark brown to lightly pigmented, cells of textura angularis, with outer layers composed of thick-walled, brown, somewhat flattened cells, becoming lighter towards the inner layers of lightly pigmented hyaline cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 4.2–6.5(–7.2) × 2.5–5 μm (x = 5.5 × 3.5 μm, n = 15), holoblastic to phialidic, hyaline, smooth, ampulliform to doliiform, lining the conidiomatal cavity. Conidia (3–)4–6.2 × 2–4.2 μm (x = 5.1 × 3.2 μm, n = 50), subglobose or ellipsoidal to cylindrical, hyaline, aseptate, smooth- and thin-walled walled, sometimes with or without guttules.

Culture characteristics:— Conidia germinating on PDA within 24 h. Colonies growing on PDA, reaching a diameter of 50 mm after 5 d at 25 °C, circular, flat, moderately dense, surface initially white, becoming pale saffron and then brown to dark brown, white near the margin; reverse black to saffron, smooth surface with entire to slightly undulate edge.

Material examined:— CHINA, Guizhou province, from fruit of Eriobotrya japonica (Thunb.) Lindl. ( Rosaceae ), 20 June 2015, Kasun M. Thambugala CN 007–2 ( MFLU 16–2599 holotype), ibid. ( GZAAS 16–0026 isotype), ex-type living culture MFLUCC 16–0489 = GZCC 15–0036

Notes:— Didymella eriobotryae is phylogenetically and morphologically closely related to D. sancta (Aveskamp, Gruyter & Verkley) Qian Chen & L. Cai , but the two species differ in having thinner conidiomatal wall and smaller conidia with less number of guttules in D. eriobotryae ( Aveskamp et al. 2009) . Didymella sancta was reported from dead branched of Ailanthus altissima (Mill.) Swingle in South Africa ( Aveskamp et al. 2009, Chen et al. 2017), while D. eriobotryae is accociated with ripe loquat fruit in China.

Figures

FIGURE 4. Didymella eriobotryae (MFLU 16–2599, holotype) a, b. Symptoms on loquat fruit (Eriobotrya japonica). c. Appearance of conidiomata sporulating on PDA. d, e. Squash mount of conidioma. f. Conidiomatal wall. g. Vertical sections through conidiomata. h. Conidiogenous cells and developing conidia. i. Conidia. Scale bars: d, e = 50 μm, f = 15 μm, g = 100 μm, h, i = 20 μm.