Colletotrichum chrysophilum W. A. S. Vieira, W. G. Lima, M. P. S. Câmara & V. P. Doyle

Gomdola, Deecksha, Jeewon, Rajesh, McKenzie, Eric H. C., Jayawardena, Ruvishika S., Al-Otibi, Fatimah, Tang, Xia, Wang, Yong, Hyde, Kevin D. & Fu, Li, 2025, Phylogenetic diversity of Colletotrichum species (Sordariomycetes, Glomerellales, Glomerellaceae) associated with plant diseases in Thailand, MycoKeys 119, pp. 137-195 : 137-195

Colletotrichum chrysophilum W. A. S. Vieira, W. G. Lima, M. P. S. Câmara & V. P. Doyle , Mycologia 109 (6): 927 (2017)

Figs 2 , 7

Description.

Associated with leaf spots of Terminalia sp. Leaf spots irregular or oval, pale brown, surrounded with a dark brown margin. Sexual morph: Not observed. Asexual morph on substrate: Conidiomata 70–120 × 60–120 µm (x ̄ = 94.5 × 96 µm, n = 10), semi-immersed, scattered, globose to subglobose, black, sometimes erumpent. Setae not observed. Conidiomatal wall 8.5–21 µm thick (x ̄ = 14.6 µm, n = 10), consisting of 3–5 layers of thick-walled pseudoparenchymatous cells of textura angularis, outer layers dark brown, inner layer pale brown to hyaline. Asexual morph on PDA: Conidiophores hyaline, smooth-walled, aseptate, unbranched. Conidiogenous cells 16–22 × 3–4.5 µm (x ̄ = 18.9 × 3.6 µm, n = 10), hyaline, cylindrical to ampulliform, straight or flexuous, tapering towards the apex. Conidia 13–19 × 4.5–6 µm (x ̄ = 15.8 × 5.1 µm, n = 30; L / W ratio = 3.1), hyaline, cylindrical or oblong, smooth-walled, guttulate, aseptate, mostly with rounded ends. Appressoria 7–12 × 7–13 µm (x ̄ = 10.9 × 10.5 µm, n = 5), hyaline, single-celled, globose to subglobose or irregular, smooth-walled.

Culture characteristics.

Colonies on PDA reaching approximately 45 mm diam. after 7 d of incubation at 25 ° C; mycelium greyish white, elevation flat or raised, aerial and filamentous with an entire or undulate margin.

Specimen examined.

Thailand • Chiang Rai Province, around the vicinity of Central Plaza , associated with leaf spots of Terminalia sp. ( Combretaceae ), 11 Jul 2019, D. Gomdola DG 01 - SM ( MFLU 25-0005 ), living culture MFLUCC 25-0006 .

GenBank accession numbers.

ITS = PV 263293; GAPDH = PV 290899; CHS 1 = PV 274250; ACT = PV 297876; TUB 2 = PV 295619; H 3 = PV 400141; and CAM = PV 299285.

Known hosts, distributions, and lifestyles

(listed chronologically). Endophytic on Theobroma cacao and Genipa americana in Panama ( Rojas et al. 2010) and Terpsichore taxifolia in Puerto Rico ( Doyle et al. 2013).

Pathogenic; anthracnose on fruits of Musa sp. in Minas Gerais, Pernambuco, Santa Catarina, and São Paulo states in Brazil and Mexico ( Vieira et al. 2017; Fuentes-Aragón et al. 2021), leaves of Anacardium humile and A. occidentale in Brazil ( Veloso et al. 2018, 2021), fruits of Mangifera indica in Mexico ( Fuentes-Aragón et al. 2020 a), fruits of Persea americana in Mexico ( Fuentes-Aragón et al. 2020 b) and Brazil ( Soares et al. 2021), leaves of Bauhinia forficata in Brazil (de Souza Junior et al. 2021), leaves of Manihot esculenta in Brazil ( Machado et al. 2021), fruits of Carica papaya in Mexico ( Pacheco-Esteva et al. 2022), and leaves of V accinium corymbosum in Brazil ( Soares et al. 2022).

Bitter rot of Malus domestica in New York ( Khodadadi et al. 2020) and Spain ( Cabrefiga et al. 2022).

Preharvest decay of Malus domestica in Italy ( Deltedesco and Oettl 2023).

Leaf spots on Euterpe oleracea and Malus domestica in Brazil and Uruguay ( Astolfi et al. 2022; dos Santos et al. 2022; Andrello et al. 2024).

Associated with leaf spots of Terminalia sp. in Thailand (this study).

Notes.

Our isolate ( MFLUCC 25-0006 ) grouped with Colletotrichum chrysophilum ( URM 7368 , A 20 _ F 13 _ 004, PP _ 212 b, PP _ 211 a, PP _ 209 c, PP _ 208 d, PP _ 210 d, and CBS 146410 ) with 100 % ML and 1.00 PP support (Fig. 2 ). Based on our phylogenetic analyses, C. chrysophilum is positioned within the C. gloeosporioides species complex (Figs 1 , 2 ), congruent with the findings of Vieira et al. (2017). No nucleotide difference was observed in ITS (495 bp), GAPDH (219 bp), CHS 1 (267 bp), ACT (216 bp), TUB 2 (648 bp), and CAM (656 bp) regions between our isolate ( MFLUCC 25-0006 ) and C. chrysophilum ( URM 7368 ).

MFLUCC 25-0006 is morphologically similar to the ex-type of C. chrysophilum ( URM 7368 ), producing hyaline, smooth-walled, guttulate, aseptate, and cylindrical or oblong conidia with rounded ends ( Vieira et al. 2017). The conidial L / W ratio of our isolate is similar to that of C. chrysophilum ( URM 7368 ) (L / W ratio = 3.1 vs. 3.1).

Based on phylogenetic and morphological species concepts, we identify our isolate as Colletotrichum chrysophilum . This study represents the first report of C. chrysophilum associated with leaf spots on Terminalia sp. and establishes a new geographical record in Thailand.

Figures

Figure 1. Maximum likelihood analysis (IQ-tree) based on a combined dataset of ITS, GAPDH, CHS 1, ACT, TUB 2, H 3, and CAM sequences from dataset 1, which includes all Colletotrichum species. 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 Monilochaetes infuscans (CBS 869.96) and M. melastomae (CBS 145059). Type, ex-type, and reference species are denoted with T. Our isolates are in bold red font, while our new species are in bold blue font. Different color blocks represent distinct species complexes, with a single color used to denote singleton species.

Figure 2. Maximum likelihood analysis (IQ-tree) based on a combined dataset of ITS, GAPDH, CHS 1, ACT, TUB 2, H 3, and CAM sequences from dataset 2, which includes all species in the C. gloeosporioides 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. beeveri (CBS 128527) and C. boninense (CBS 123755), belonging to the C. boninense 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 7. Colletotrichum chrysophilum. a. Leaf spot (Terminalia sp.); b. Close up of a leaf spot; c. Conidiomata on substrate; d, e. Top and reverse of colony on PDA after 3 d f Section through a conidioma; g. Conidiomatal wall; h, i. Conidiogenesis and developing conidia; j, k. Appressoria; l, m. Conidia. Scale bars: 1 mm (b); 200 μm (c); 50 μm (f); 10 μm (g – m).