Colletotrichum syzygicola Udayanga, Manamgoda & K.D. Hyde [as ‘syzygicola‘]

Classification – Glomerellaceae, Glomerellales, Hypocreomycetidae, Sordariomycetes, Ascomycota

Index Fungorum number – IF545019; Facesoffungi number – FoF 00015

Other useful webpages – outlineoffungi.org; fungalgenera.org; Sordariomycetes.org; coelomycetes.org

Description – Associated with leaf spot of Cymbidium sp. Sexual morph: undetermined. Asexual morph: ceolomycetous. Conidiophores unbranched, smooth, hyaline. Conidia 15–20 × 5–10 μm (av. 17 × 5 μm, n = 50), aseptate, most rounded at both ends, cylindrical, some rounded at the ends, curved at the ends. Appressoria 10–20 × 5–10 μm (av. 13 × 6 μm, n = 30), often becoming complex with age, some rhomboid, long, some quincunx, 10–15 × 10–12 μm (av. 12 × 9 μm, n = 30), long, dark brown.

Culture characteristics – Colonies on PDA attaining 60 mm in diam in 7 days at 25 ℃, growth rate per day 4.59 ± 0.5mm/d, at first white, becoming greyish brown, in reverse dark brown and margin white. Aerial mycelium greyish brown at the centre, dense, cottony, without setae.

Material examined – China, Guangdong Province, Shenzhen Botanical Garden, Cymbidium sp. (Orchidaceae), 30 November 2020, J.W. Chen, Z.L. Mai, C. Chen, (dried cultures ZHKU 21-0078 and ZHJU 21-0079), living cultures ZHKUCC 21-0085 and ZHJUCC 21-0086, new host record.

GenBank accession numbers – gapdh: OL672729, OL672730; act: OL579738, OL672709; chs-1: OL672719, OL672720; tub2: OL739539, OL739540.

Notes – See Manawasinghe et al. (2022).

Colletotrichum syzygicola (ZHKUCC 21-0085, new host record). a, b Upper and reverse view on PDA after seven days. c Conidiogenous cells. d, e Conidiogenous cells with developing conidia. f–h Conidia. i–n Appressoria. Scale bars: c–n = 10 µm.

Maximum likelihood tree inferred from the combined ITS, gapdh, act, chs-1 and tub2 sequence data for Colletotrichum endophytica, C. fructicola, C. pandanicola, and C. syzygicola. The tree is rooted to Colletotrichum boninense (CBS123755 and ICMP 18596). Maximum parsimony and maximum likelihood bootstrap support values equal to or greater than 50% are given at the nodes and branches (MP/ML). The new isolates from South China region are indicated in red.