Colletotrichum dracaenigenum Chaiwan & K.D. Hyde, 2021

Chaiwan, Napalai, Tibpromma, Saowaluck, Jayawardena, Ruvishika S., Mapook, Ausana, Wanasinghe, Dhanushka N., Mortimer, Peter E., Lumyong, Saisamorn & Hyde, Kevin D., 2021, Colletotrichum dracaenigenum, a new species on Dracaena fragrans, Phytotaxa 491 (2), pp. 143-157 : 148

Colletotrichum dracaenigenum Chaiwan & K.D. Hyde , sp. nov.

Index Fungorum Number. IF 557582, Facesoffungi Number. FoF06301; FIGURE 2–3 .

Etymology: The specific epithet “ dracaenigenum ” refers to the host genus Dracaena , from which the holotype was collected.

Holotype: MFLU 18–1856

Saprobic on dead leaves of Dracaena fragrans (L.). Sexual morph: Ascomata 140–160 × 190–250 μm (x = 147 × 217.5 µm, n = 5), semi-immersed, uniloculate, solitary, subglobose to ovoid, dark-brown to black, ostiolate, lacking setae. Peridium 10–20 µm wide, comprising 2–3 layers of dark-brown to pale brown cells, arranged in a textura angularis. Paraphyses hyaline, smooth-walled, cylindrical, with a round tip, septate, apically free, 20–45 μm long, at the basis 4–6 μm wide. Asci 35–40 × 8–10 μm (x = 37.5 × 9 μm, n = 20), 6–8-spored, unitunicate, broad cylindrical to clavate, tapering to apex and base, or rounded at apex, pedicellate at base, sometimes sessile, smooth-walled. Ascospores 7–10 × 4–5 μm (x = 8.5 × 4.5 μm, n = 20), cylindrical, sometimes slightly curved, tapering towards rounded ends, hyaline, smooth-walled, aseptate, contents granular. Asexual morph: developed on PDA. Vegetative hyphae 2–6.5 μm wide, hyaline, smooth-walled, septate, branched. Setae not observed. Conidiophores hyaline to pale brown, smooth-walled, unbranched. Conidiogenous cells 13–15 × 3.5–5 μm (x = 14 × 4.5 μm, n = 10), hyaline to pale brown, cylindrical to clavate, monoblastic, holoblastic, integrated, terminal, cylindrical, each with single conidium. Conidia 9–16 × 2–5 μm (x = 12.5 × 3.5 μm, n = 20), hyaline, aseptate, smooth-walled, cylindrical, both ends rounded, contents granular. Appressoria single or short chains, dark brown, irregular, but often to navicular in outline, the margin entire to undulate, 5–12 × 4–7 µm, (x = 8.5 × 5.5 μm, n = 20).

Culture characteristics: Colonies growing on PDA, circular, umbonate, rough and wrinkled at surface, edge entire, grey to dark in center, aerial mycelium reaching 85 mm in 7 days at room temperature, pale grey to dark grey, conidia in mass orange, mycelium superficial and partially immersed, branched, septate, hyaline to dark grey, smooth.

Material examined: Thailand, Chumphon Province, Phato District, Pang Wan, on Dracaena fragrans , 2 September 2017, Napalai Chaiwan , NCCP002 ( MFLU 18–1856 , holotype; HKAS111933 Isotype) , ex-type living culture, MFLUCC 19–0430 , MFLUCC19–0431 .

Figures

FIGURE 2. Sexual morph of Colletotrichum dracaenigenum (MFLU 18–1856, holotype). a. Dracaena fragrans. b, c, d. Appearance on host surface. e. Vertical section of ascomata. f. Peridium. g. Paraphyses. h, i. Asci. j–o.Ascospores. Scale bars: a = 2 cm, b, c = 2000 μm, e = 100 μm, g = 20 μm, f, h-i = 10 μm, j–o = 5 μm.

FIGURE 3. Asexual morph of Colletotrichum dracaenigenum (MFLUCC 19–0430,). a. Culture on PDA. b, c. Salmon colored spore mass produced in culture. d, e. Conidiophore. f–i. Conidiogenous cell. j–m. Conidia. n–t. Appressoria. Scale bars: b = 2 mm, c= 1 mm, n–t = 20 μm, f–m = 10 μm.