Dictyoarthrinium sacchari (J.A. Stev.) Damon, Bull. Torrey bot. Club 80: 164 (1953) Fig. 6
= Tetracoccosporium sacchari Stevenson apud Johnston and Stevenson, Jour. Dept. Agr. Porto Rico 1(4):225. 1917.
= Dictyoarthrinium quadratum Hughes, Mye. Paper (C. M. I.) No. 48: 30. 1952.
MycoBank number: MB 296617; Index Fungorum number: IF 296617; Facesoffungi number: FoF 08468;
Saprobic on dead woody twigs of Lithocarpus sp. Sexual morph: Undetermined. Asexual morph: Colonies solitary, granular, black. Mycelium superficial, septate, branched, anastomosing hyphae. Conidiophores 70–140 × 4.5–5 μm (x̅ = 101 × 4.8 μm, n = 15), erect, macronematous, basauxic, cylindrical, straight or flexuous, subhyaline to pale brown, the transverse septa partly brown with distances of 3–8 μm, rough-walled, arising from the conidiophore mother cell. Conidiophore mother cells 3.7–4.8 × 3.3–4.1 μm (x̅ = 4.5 × 4 μm, n = 10), cup-shaped, unbranched, pale brown. Conidiogenous cells 4–6 × 4–5 μm (x̅ = 4.9 × 4.4 μm, n = 10), blastic, integrated, terminal and intercalary, cylindrical, subhyaline. Conidia 9–11 × 8.5–11 μm (x̅ = 10.2 × 10 μm, n = 30), solitary, holoblastic, 1-celled or 2-celled and subhyaline to pale brown at young, cruciately septate with 4-cells, slightly constricted at the septa, rounded at the corners, spherical or subspherical, brown to dark brown at maturity, with brown warts on the surface of the cells, verrucose, mature conidia split along one line of the septa, arising from the lateral or apical part of conidiophores.
Culture characteristics ‒ Colonies on PDA, reaching 40–50 mm diam. at 14 days at room temperature (25–30 ℃), superficial, circular, umbonate at the center, surface rough, with sparse mycelia, radially furrowed, margin crenulate, from below and below white.
Known distribution ‒ Hosts Cosmos bipinnatus, Cymbopogon citrates, Delonix elata, Lithachne pauciflora, Musa paradisiaca, Musa acuminate, Neolitsea scrobiculata, Persea mechrantha, Pinus wallichiana, Prunus amygdalus, Saccharum officinarum, Saccharum spontaneum, Allium, Ananas, Asparagus, Bambusa, Borassus, Cajanus, Capsicum, Cassia, Citrus, Cymbopogon, Delonix, Dendrocalamus, Dracaena, Eichhornia, Erianthus, Erythrina, Euphorbia, Gossypium, Ipomaea, Lycopersicon, Mimusops, Musa, Oldenlandia, Oryza, Panicum, Phragmites, Pinus, Saccharum, Triticum, Viola, Zinnia (Bhardwaj et al. 2020, Samarakoon et al. 2020b, Maharachchikumbura et al. 2021).
Distribution ‒ Brazil, Brunei, Cuba, Egypt, Ghana, India, Malaysia, Nigeria, Pakistan, Puerto Rico, Sri Lanka, Sudan, Solomon Islands, Spain, States of Micronesia, Thailand, Venezuela, Zambia, and Zimbabwe (Damon 1953, Samarakoon et al. 2020b, Maharachchikumbura et al. 2021).
Material examined ‒ Thailand, Chiang Rai province, Mae Yao District, on dead woody twigs of Lithocarpus sp., 23 September 2019, G.C. Ren, MY23-1 (KUN-HKAS 122786), living culture KUMCC 21-0632.
Notes ‒ Dictyoarthrinium sacchari was introduced by Damon (1953) based on morphology. This species is widely distributed throughout the globe and reported from different hosts (Damon 1953, Bhardwaj et al. 2020, Samarakoon et al. 2020b). Vu et al. (2019) submitted the LSU sequence data to NCBI, and Samarakoon et al. (2020) conducted the first detailed molecular investigation (SSU, LSU, ITS, tef1–α) on D. sacchari. The characters of our new strain of Dictyoarthrinium sacchari (KUMCC 21-0632) are similar to the type strain of D. sacchari (Damon 1953). However, our isolate has slight differences in morphology, such as the length of conidiophores and the size of conidia, compared to other Dictyoarthrinium sacchari collections. The multi-gene phylogenetic analysis based on combined SSU, LSU, ITS and tef1–α sequence data showed that our isolate is monophyletic with Dictyoarthrinium sacchari (CBS 52973) (Fig. 1). Based on morphological characteristics and phylogenetic analysis, we report KUMCC 21-0632 as a new host record of Dictyoarthrinium sacchari from decaying wood of Lithocarpus sp. in Thailand.
Figure 6 ‒ Dictyoarthrinium sacchari (KUN-HKAS 122786) a–c Conidia on the host. d–f Conidia with conidiophores on stalk. g–k Immature conidium. i–k Warted four-celled mature conidia. l Germinated conidium. m, n Culture characters on PDA. Scale bars: d–f = 50 μm, g–k = 10 μm, l = 20 μm, m, n = 30 mm.