Colletotrichum schimae
Colletotrichum schimae F. Liu, W.P. Wu & L. Cai, in Liu, Ma, Hou, Diao, Wu, Damm, Song & Cai, Stud. Mycol. 101: 38 (2022)
Index Fungorum number: IF841391 Facesoffungi number:17279
Associated with leaf spots of Jasminum sp. Leaf spots circular, pale brown to brown. Sexual morph: Not observed. Asexual morph on PDA: Conidiomata 200–1000 µm diam. (x̄ = 400 µm, n = 10), semi-immersed, scattered or segregated, globose to subglobose, dark brown to black, exuding glistening yellowish to orange conidial mass. Setae not observed. Conidiophores formed directly from mycelium, hyaline, sometimes septate. Conidiogenous cells 16–45 × 2–4.5 µm (x̄ = 32 × 3.5 µm, n = 10), formed terminally or laterally on hyphae, hyaline, cylindrical, solitary or branched, straight or flexuous, tapering towards the apex. Conidia 9–15 × 2.5–4 µm (x̄ = 11.5 × 3.5 µm, n = 30; L/W ratio = 3.3), hyaline, cylindrical to fusiform, smooth-walled, guttulate, aseptate, mostly with acute ends. Appressoria not observed.
Culture characteristics: Colonies on PDA reaching approximately 40 mm diam. after 7 d of incubation at 25 °C; mycelium initially white, becoming yellowish to olivaceous brown with age; elevation flat, with an entire margin.
Material examined: Thailand, Chiang Mai Province, Doi Inthanon National Park, Kew Mae Pan nature trail, associated with leaf spots of Jasminum sp. (Oleaceae), 20 Oct 2021, D. Gomdola DGJas1(L2)-A (MFLU 25-0001, BHH 50476), living culture MFLUCC 25-0002; DGJas1(L3)-B (MFLU 25-0002, BHH 50478), living culture MFLUCC 25-0003
GenBank accession number: MFLUCC 25-0002; ITS = PV263289; GAPDH = PV290895; CHS1 = PV274246; ACT = PV297872; and TUB2 = PV295615; MFLUCC 25-0003; ITS = PV263290; GAPDH = PV290896; CHS1 = PV274247; ACT = PV297873; and TUB2 = PV295616.
Notes: Our isolates (MFLUCC 25-0002 and MFLUCC 25-0003) grouped with Colletotrichum schimae (LC13880, LC13881, PC9, CNUCC 324C-1-5-2, and CNUCC 528-2-2) with 97% ML and 0.98 PP support. In our phylogenetic analyses, C. schimae is positioned within the C. acutatum species complex consistent with the findings of Liu et al. (2022) and Sui et al. (2024). Nucleotide sequence comparisons between our two isolates and C. schimae (LC13880) showed no differences in ITS (494 base pairs, bp), GAPDH (215 bp), and TUB2 (490 bp) regions. However, a 0.8% sequence divergence (2/245 bp) was observed in the CHS1 gene between our isolates and the ex-type of C. schimae (LC13880). For ACT, no differences were found between MFLUCC 25-0002 and C. schimae (LC13880), but a 1.9% divergence (4/208 bp) was observed between MFLUCC 25-0003 and C. schimae (LC13880). MFLUCC 25-0002 and MFLUCC 25-0003 morphologically resemble the ex-type of C. schimae (LC13880) with hyaline, cylindrical conidiogenous cells and hyaline, smooth-walled, guttulate, and cylindrical to fusoid conidia with acute ends (Liu et al. 2022). Additionally, the conidial length-to-width ratio (L/W) of our isolates is similar to that of C. schimae (LC13880) (L/W ratio = 3.3 vs. 3.3). Based on phylogenetic and morphological species concepts, we identify our isolates as Colletotrichum schimae. This study represents the first report of C. schimae associated with leaf spots on Jasminum sp. and establishes a new geographical record in Thailand.
Figure 1. Maximum likelihood analysis (IQ-tree) based on a combined dataset of ITS, GAPDH, CHS1, ACT, TUB2, H3, and CAM sequences from dataset 4, which includes all species in the Colletotrichum acutatum species complex. Bootstrap support values (ML ≥ 80%) and Bayesian posterior probabilities (PP ≥ 0.95) are given above the branches or near the nodes as ML/PP. Hyphens (--) indicate bootstrap support values below 80% for ML and posterior probabilities below 0.95. The tree is rooted with C. dematium (CBS 125.25) and C. parthenocissicola (MFLUCC 17-1098), belonging to the C. dematium species complex. Type, ex-type, and reference species are denoted with T. Our isolates are in bold red font. Different color blocks represent distinct species complexes.
Figure 2. Colletotrichum schimae. a. Leaf spots (Jasminum sp.); b. Top and reverse of colony on PDA after 7 d; c. Conidiogenesis and developing conidia; d–i. Conidia. Scale bars: 10 μm. The scale bar (i) applies to d–h.
References
Recent Genus
AmphisphaeriaParaeutypella
Halorosellinia
Recent Species
Torula chromolaenaePericonia delonicis
Neopestalotiopsis theobromicola