Colletotrichum karsti You L. Yang, Zuo Y. Liu, K.D. Hyde & L. Cai [as ‘karstii‘]
Classification – Glomerellaceae, Glomerellales, Hypocreomycetidae, Sordariomycetes, Ascomycota
Index Fungorum number – IF581687; Facesoffungi number – FoF 09442
Other useful webpages – outlineoffungi.org; fungalgenera.org; Sordariomycetes.org; coelomycetes.org
Description – Associated with leaf spot of Aglaonema sp. and Cymbidium sinense. Sexual morph: Ascomata 140–190 × 120– 150(–180) μm (av. 168 × 139 μm, n = 30), forming after 4 weeks, solitary, superficial or immersed, black, subglobose to obpyriform, ostiolate. Asci (48–)53–70 × 10–14 μm (av. 58 × 12 μm, n = 50), smooth-walled, cylindrical to clavate, tapering to apex and base, 8-spored. Ascospores 15–18(–21) × 6–8 μm (av. 17 × 7 μm, n = 50), uni- or bi-seriately arranged, aseptate, hyaline, fusiform to ovoid, slightly curved. Asexual morph: Vegetative hyphae 1–5 µm diam., hyaline, smooth-walled, septate, branched. Conidiomata black, scattered. Setae not observed. Conidiophores 100 μm long, hyaline to pale brown, smooth, septate, branched. Conidiogenous cells 9–20 × 3–5 µm (av. 16 × 4 μm, n = 30), hyaline or pale brown, smooth, cylindrical to elongate-ampulliform. Conidia 13–16(–21) × 5–7 µm (av. 15 × 6 µm, n = 30), straight, hyaline, smooth-walled, aseptate, cylindrical, both ends rounded, contents granular. Appressoria 8–13 × 5–7(–9) µm (av. 10 × 6 µm, n = 30), single or in groups, medium to dark brown, navicular to bullet-shaped, with entire edge.
Culture characteristics –Colonies on PDA reaching 70 mm diam. after 7 days at 25 ℃, circular, regular, white-pink, mycelium lush, flocculent, reverse orange, producing black ascomata and orange conidial masses.
Material examined – China, Guangdong Province, Meizhou City, on leaf spot of Aglaonema sp. (Araceae), October 2021, Yunxia Zhang and Jingwen Chen (ZHKUCC 23-0858, new host record).
Additional materials – China, Guangdong Province, Meizhou City, on leaf spot of Cymbidium sinense (Jack. ex Andr.) Willd. (Orchidaceae), October 2021, Yunxia Zhang and Jingwen Chen (living culture ZHKU 23-0857, new host record); China, Hunan Province, Changsha City, on leaf spot of Rosa chinensis Jacq. (Rosaceae), August 2022, Chao Chen (living culture ZHKUCC 23-0860, new host record).
GenBank accession numbers – gapdh: OR493868, OR493869, OR493870, OR493871; act: OR493812, OR493813, OR493814, OR493815; chs-1: OR493840, OR493841, OR493842, OR493843; ITS: OR286087, OR286088, OR286088, OR286090; tub2: OR453354, OR453355, OR453356, OR453357.
Notes – See Zhang et al. (2023).
Colletotrichum karsti (ZHKUCC 23-0858, new host record). a, b Upper and reverse view on PDA (7 d). c, d Ascomata. e Asci. f Ascospores. g Conidial masses. h, i Conidiogenous cells. j Conidia. k–n Appressoria. Scale bars: d = 20 µm, d–f, h–n = 10 µm.
Maximum likelihood tree inferred from the combined ITS, gapdh, chs-1, act, and tub2 sequence data for Colletotrichum chamaedoreae, C. cymbidiicola, and C. karsti. The tree is rooted to C. truncatum (CBS 151.35). Maximum likelihood bootstrap support values equal to or greater than 70% and Bayesian posterior probabilities equal to or greater than 0.90 are given at the nodes and branches (ML/BYPP) . Ex-type isolates are marked with “T”. The new isolates from South China region are indicated in red.