Verruconis thailandica Giraldo López & Crous

Erandi Yasanthika, W. A., Tennakoon, Danushka S., Gomes De Farias, Antonio R., Thilini Chethana, K. W., Bhat, D. Jayarama & Wanasinghe, Dhanushka N., 2023, Isolation and characterization of novel Dothideomycetes species from forest soils in Chiang Rai and Krabi (Thailand): additions to the diversity of Curvularia and Verruconis, Phytotaxa 609 (1), pp. 17-44 : 35-36

Verruconis thailandica Giraldo López & Crous , Fungal Systematics and Evolution 6: 21 (2020)

Index Fungorum number: IF833679, Faces of fungi number: FoF09618, FIGURE 6 .

Asexual morph: Conidiophores 1–2 μm (x = 1.8 μm, n=20) wide, macronematous, mononematous and synnematous, erect, straight, or slightly bent, simple, sub-cylindrical, hyaline to pale brown, smooth-walled, conidiogenesis terminal or intercalary, sympodial. Conidiogenous cells 2–3.5 × 1.5–3 μm (x = 3 × 1.8 μm, n = 20), monoblastic, discrete, sub-cylindrical to ampulliform. Conidia 5–7 × 2.2–3.1 μm (x = 5.8 × 2.6 μm, n = 20), broadly ellipsoidal or rarely oval, hyaline to pale brown, 1-septate, constricted at the septum, verrucose, thick-walled, protuberant hilum. Sexual morph: Undetermined.

Culture characteristics:— Colonies on PDA at 25 °C after 7 days become 4 cm diam., filamentous margined, hairy, and raised, brown to grayish brown at centre, flat, glabrous, dark brown at periphery, reverse dark brown, diffusible brownish pigment. Mycelium hyaline, aseptate, smooth at immature become septate, pale brown, 1–3 (x = 2.5) μm diam. hyphae.

Known hosts and substrates:— soil ( Hernández-Restrepo et al. 2020, this study).

Known distribution:— Thailand ( Hernández-Restrepo et al. 2020, this study)

Material examined:— Thailand, Chiang Rai Province, 19°53’2” N, 100°5’37” E, 440m, from forest soil, 7 January 2020, W.A.E. Yasanthika ( MFLU 22-0258 ); living culture, MFLUCC 22-0083 .

Notes— Verruconis thailandica (CBS 145768) was first isolated from soil near a waterfall in Nakhon Nayok Province, Thailand ( Hernández-Restrepo et al. 2020). Verruconis thailandica has a closer phylogenetic affinity to V. verruculosa and V.terricola ( Hernández-Restrepo et al. 2020) ( FIGURE 1 ). Our collection is grouped with V.thailandica isolates (CBS 145768, GUCC 18267) in a well-supported clade with 100% ML, 1.00 BYPP support, and related to the isolate CBS 145768 with 97% ML and 1.00 BYPP. Our strain morphologically resembles V. thailandica (CBS 145768) by having erect, straight or slightly bent, sub-cylindrical conidiophores and broadly ellipsoidal or rarely oval, 1-septate conidia ( Hernández-Restrepo et al. 2020). We observed mononematous and synnematous conidiophores in our isolate (MFLUCC 22-0083), which were missing in the type species (CBS 145768). This morphological variation can be due to the environmental adaptations of the organism ( Francisco et al. 2019). Therefore, with morpho-molecular justifications, we present the second report of V. thailandica from forest soils in Thailand.

Figures

FIGURE 1.Maximum likelihood phylogenetic tree generated of the combinedITS-GAPDH-tef1-α sequence data forCurvularia. Bootstrap support values of maximum likelihood greater than 60% and Bayesian posterior probabilities (BYPP) greater than 0.95 are indicated above the nodes. Newly added strains are in blue and ex-type strains are in bold. The tree is rooted to Bipolaris maydis (CBS13629P) and B. panici-miliacei (CBS 19929). Isolated substrates/ habitat is indicated in triangles. Black: Human/ animal, green: plants, brown: soil, pink: air, blue: aquatic habitat. unknown:empty

FIGURE 6. Verruconis thailandica (MFLU22-0258, new record) a. Colony from above (on PDA). b. Colony from below (on PDA). c. Sporulated colony with conidial attachments on the mycelium. d. Immature hyphae e. Mature septate hyphae. f. Conidiogenesis synnematous. g–j. Conidiogenesis mononematous conidiophores. k–p Conidia. Scale bars: d, e = 20 μm, f–l, n = 10 μm, m, o, p = 5 μm.