Colletotrichum plurivorum Damm, Alizadeh & Toy. Sato, in Damm, Sato, Alizadeh, Groenewald & Crous, Stud. Mycol. 92: 31 (2018)

MycoBank number: MB 824228; Index Fungorum number: IF 824228; Facesoffungi number: FoF 10691; Fig. 1

Associated with anthracnose on leaf spots of Aglonema sp. Sexual morph: Not observed. Asexual morph: Conidiomata produced on leaves, acervular, dark brown, bearing conidial mass and setae. Setae brown to dark brown, verruculose, 2–4-septate, 95–145 μmlong (x̅=127.5 µm, n=10),base sylindrical, slightly serrate, 4.5–6.5 μm diam (x̅= 5 µm, n = 10), tip obtuse to acute. Conidiophores rarely observed, pale brown, septate, simple or branched, 27–42 μm diam. Conidiogenous cells hyaline, cylindrical to clacate, 15–21×3.5–4.5 μm (x̅=18×4 µm, n=20). Conidia hyaline, aseptate, smooth-walled, cylindrical, straight or slightly narrow at the base, rounded at ends, guttulate, 17–23 × 5–6 μm (x̅=21.5 × 5.7 µm, n=30).

Culture characteristics – Colonies on PDA 70–90 mm after 7 days, cottony, circular, entire in margin; aerial hyphae medium in dense, greenish olivaceous in center and white in margin, reverse black-green-olivaceous in margin. Colonies on OA 67–73 mm after 7 days, flat, entire in margin, surface white to pale olivaceous grey, reverse olivaceous grey.

Material examined – Thailand, Chiang Rai Province, Mueang Chiang Rai District, Tha Sut Sub-district, on leaf spots of Aglonema sp., 03 January 2022, Alireza Armand, A16 (MFLU 23-0443); (MFLUCC 23-0284).

GenBank numbers – ITS: OR793878; act: OR804449; chs-1: OR804451; gapdh: OR804453; tub: OR804455

Notes – Strains of C. plurivorum clustered together with our strain in a distinct clade with a high bootstrap value (Fig. 2). Base pair differences between C. plurivorum (MFLUCC 23-0284) and C. plurivorum (CBS 125474) revealed 0.2% (1/538 bp) in ITS, 0.7% (2/258 bp) in act, 0.3% (1/273 bp) in chs-1, 0.7% (4/533) in tub2 and no differences in gapdh. Morphologically, C. plurivorum (MFLU 23-0443) is similar to C. plurivorum, described by Damm et al. (2019), in the shape of conidia and conidiophores. However, our strain produced longer conidiophores (27–42 μm diam., in C. plurivorum (MFLU 23-0443) vs. 30 μm in the type strain), longer conidiogenous cells 15–21 × 3.5–4.5 μm in C. plurivorum (MFLU 23-0443) vs. 7–19 × 4–5.5 μm in type strain) and longer conidia (17–23 × 5–6 μm in C. plurivorum (MFLU 23–0443) vs (15–)16.5–20 (–22.5) × (5–) 5.5–6.5(–8) μm in type strain) (Damm et al. 2018). This is a new host record for the occurrence of C. plurivorum on Aglonema.

Figure 1 – Colletotrichum plurivorum (MFLU 23–0443), a, b. The host leaves with symptoms. c. Acervuli on the host. d. Setae. e–g. Conidiogenous cells and conidial attachment. h–j. Conidia. k. Upper and reverse view of culture on PDA. Scale bars: d=50 µm, e–g=20 µm, h–j=10 µm

Figure 2 – Phylogenetic tree of Colletotrichum orchidearum and C. magnum species complexes generated by maximum parsimony analysis of combined ITS, act, chs-1, gapdh and tub2 sequence data. The tree was rooted with C. dracaenophilum (CBS 118199) and C. tongrenense (GMBC 0209). Maximum likelihood and Maximum parsimony bootstrap support values≥50% (BT) as well as Bayesian posterior probabilities≥0.90 (PP) are shown respectively near the nodes. Type strains are in bold, and the newly generated isolates are in red