Colletotrichum douhua H.L. Hu, Y.Ping Hu, Hao Yu & X.Z. Zhou [as ‘duohuaense‘], in Cao et al., Fungal Diversity 132: 477 (2025)

Index Fungorum number: IF 571122; MycoBank number: MB 571818; Facesoffungi number: FoF 17241; Figs. 1, 2

Etymology – refers to the Chinese specific epithet of the host Polygonatum cyrtonema Hua, means multiflowers

Holotype – CGMCC 3.24303.

Asexual morph: the leaves first with reddish-brown anthracnose on Polygonatum cyrtonema, later the spots expanded irregularly, the center part became yellow gray, the out part kept reddish-brown. The Koch’s postulates confirmed its pathogenicity. Acervulus light brown. Conidiophores hyaline, straight or lightly curved, fence-like formed along the acervulus. Conidiogenous cells hyaline, ampulliform to doliiform, blastic. Conidia typically one celled, hyaline, long ellipsoid, with several droplets, 13.8–17.2 × 4.9–6.2 µm, x̄ = 15.3 ± 0.9 × 5.5 ± 0.3 µm, and n = 50. Sexual morph: not observed.

Cultural characteristics – Colonies on PDA reaching 7.3 cm at 26°C after 7 d in dark. Colony gray-white to white, with plenty of aerial hyphae, velvet texture. Orange conidial mass formed after cultured on OA for 15 d at 26. in dark.

Material examined – CHINA, Fujian Province, Jian’ou City, Yushan Town, Dingdun Village, 27°01’29″N 118°33’36″E, 720 m asl, 22 Jul. 2021, Hong-Li Hu, Yan Ping Hu, Hao Yu and Xian-Zhi Zhou, D1_DY1_C1 (CGMCC 3.24303, holotype), D1-DY3-A, D1-DY5-A, D1-DY6-A, D1-DY7-C-2.

GenBank – CGMCC 3.24303: PP095136 (ITS), PP092234 (gapdh), PP092229 (chs-1), PP092219 (act), PP092224 (cal); D1-DY3-A: PP095137 (ITS), PP092235 (gapdh), PP092230 (chs-1), PP092220 (act), PP092225 (cal); D1-DY5-A: PP095138 (ITS), PP092238 (gapdh), PP092233 (chs-1), PP092221 (act), PP092226 (cal); D1-DY6-A: PP095139 (ITS), PP092236 (gapdh), PP092231 (chs-1), PP092222 (act), PP092227 (cal); D1-DY7-C-2: PP095140 (ITS), PP092237 (gapdh), PP092232 (chs-1), PP092223 (act), PP092228 (cal).

Notes – Colletotrichum duohuaense was isolated from diseased leaves of Polygonatum cyrtonema. There have been five Colletotrichum species reported on P. cyrtonema, and two are in Colletotrichum gloeosporioides species complex, i.e., C. fructicola and C. gloeosporioides (Dan et al. 2023a, b). However, they didn’t cluster with C. duohuaense in the phylogenetic tree. Colletotrichum duohuaense, C. henanense and C. yulongense were distributed in the same clade with high support (BS = 100%, PP = 1.00). But the spores of C. duohuaense is obviously larger than C. henanense (8–17 × 3–5.5 µm, av ± SD = 12.5 ± 1.8 × 4.5 ± 0.6 µm) and C. yulongense (11–13 × 4–5 µm, mean ± SD = 12.0 ± 1 × 4.5 ± 0.5 µm) (Liu et al. 2015b; Wang et al. 2019). Thus, C. duohuaense is reported as a new species.

Figure 1 – Colletotrichum duohuaense (CGMCC 3.24303, holotype). a Infected leave. b CK for Koch’s postulates. c Leave inoculated with C. duohuaense. d Colony cultured on PDA for 7d. e Conidial mass (cultured on OA for 15d). f Acervulus and conidiophores. g Conidiogenous cells. h Conidia. Scale bars: e = 100 µm, f–g = 20 µm, h = 10 µm.

Figure 2 – Maximum Likelihood phylogram of Colletotrichum gloeosporioides species complex based on a combined matrix of ITS, gadpd, chs-1, act and cal genes [Colletotrichum boninense (CBS 123755) is the outgroup]. Numbers in front of slash stand for the Maximum Likelihood bootstrap values, and numbers behind the slash stand for the Bayesian posterior probabilities. “-” indicates that the given branches were supported less than 50% by Maximum Likelihood bootstrap or 0.93 by Bayesian analyses. The new species are in red.