Periconia echinochloae (Bat.) M.B. Ellis, Dematiaceous Hyphomycetes (Kew)

Madagammana, Ashani D., Phukhamsakda, Chayanard, Bhunjun, Chitrabhanu S., Rathnayaka, Achala R., Bhat, D. Jayarama, Alotibi, Fatimah & Hyde, Kevin D., 2024, Novel Hosts, Geographical Records, and A Global Checklist of molecularly confirmed Periconia species, Phytotaxa 674 (1), pp. 18-54 : 27

Periconia echinochloae (Bat.) M.B. Ellis, Dematiaceous Hyphomycetes (Kew) : 347 (1971)

≡ Periconiella echinochloae Batista & Vital, Bol. Secr. Agric. (Pernambuco) 19(1-2): 174 (1952)

= Periconia imperatae Z.H. Lu, P.W. Su, & Maharachch. , in Su, Lu, Tian, Chen & Maharachchikumbura, J. Fungi 2023, 9(3), 300 (2023).

Index Fungorum number: IF 319348, Figure 4

Saprobic on Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs. Sexual morph: Undetermined. Asexual morph: Colonies on the natural substrate numerous, effuse, dark brown to black, floccose. Conidiophores 230–240 × 7.5–9.5 μm (x̄ = 238 × 8 µm, n = 10), macronematous, mononematous, straight or slightly flexuous, branched, bifurcate, solitary or fasciculate, rarely 1–2 together, brown to dark brown, 3–7-septate, smooth to minutely verruculose, thick-walled. Conidiogenous cells polyblastic, pale brown to brown, terminal, integrated or discrete, oval to subglobose, smooth to verruculose. Conidia 14–18 × 6–9 µm (x = 15.4 × 7 µm, n = 10), solitary, ellipsoid to obovoid, initially faint yellow or pale brown, becoming brown to dark brown at maturity, aseptate, verrucose.

Culture characters: Colonies on PDA reaching 50 mm diam. after 14 days at 25 °C, irregular with smooth margin, slightly woolly, flattened, yellow toward the middle; yellow at the margin, and yellow to brown at the middle in reverse; producing yellow pigments on PDA.

Material examined: Thailand, Chiang Rai, Tha Sut sub district, Mueang district, on recently dead flowers of Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs ( Poaceae ) flowers, 28 January 2023, collected and identified by Ashani Madagammana, AD 0410 (MFLU23-0454); living cultures MFLUCC 23-0295.

Know hosts and distribution: Androphogon, Brachiaria , Cenchrus , Echinochloa , Heteropogon , Oryza , Panicum , Saccharum , Sorghum , and Zea (Poaceae) in Australia, Brazil, British Solomon Island Protectorate, Cuba, Ethiopia, India, Jameica, Kenya, New Guinea, Sierra Leone, Sudan Republic, Uganda, and Zambia ( Ellis 1971), Imperata cylindrica (L.) Raeusch. ( Poaceae ) in China ( Su et al. 2023), Musa sp. in Thailand ( Samarakoon et al. 2024) and Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs ( Poaceae ) flowers in Thailand (this study).

Notes: Based on the BLAST results, our sequences showed high similarity to different strains of P. echinochloae and P. imperatae for the ITS, LSU, rpb2, and tef 1-α sequences. However, different Periconia species showed high similarity based on SSU sequence. According to phylogenetic analyses, our isolate (MFLUCC 23-0295) grouped with the strain of P. echinochloae (MFLU 23-0228) reported in Thailand. Furthermore, both our isolate and P. echinochloae (MFLU 23-0228) grouped with the ex-type strain (CGMCC 3.23931) and other authentic strains (UESTCC 22.0145; UESTCC 22.0146) of P. imperatae reported in China ( Figure 1 ). Our species was isolated from specimens collected from dead flowers of Megathyrsus maximus in Chiang Rai, Thailand. Based on conidia and conidiophore morphology as well as culture characteristics, our isolate is similar to the holotype (HKAS 126517) of P. imperatae , which was collected from dead leaves and culms of Imperata cylindrica ( Poaceae ) in China ( Su et al. 2023). However, the lengthto-width ratio of conidia is different. Furthermore, our isolate is similar to the description of P. echinochloae provided by Ellis (1971). The morphological characters of P. echinochloae and P. imperatae are tabulated in Table 3. We identify our fungal strain as P. echinochloae based on morphology and phylogeny. However, previously, P. echinochloae were reported in Megathyrsus species (as Panicum ) and also reported in Thailand. Therefore, this is the second report of P. echinochloae from Thailand.

Figures

FIGURE 1. Phylogram generated from maximum likelihood based on the SSU-ITS-LSU-tef1-α-rpb2 matrix. The tree was rooted with Massarina cisti (CBS 266.62) and Massarina eburnea (CBS 473.64). Bootstrap support values for ML ≥ 75% and PP ≥ 0.90 are provided at the nodes. Strains isolated in this study are in red and ex-type strains are in bold. Strains synonymized in this study are indicated in blue.

FIGURE 4. Periconia echinochloae (MFLU 23-0454). a. Host in their natural habitat; b. Dead flowers of Megathyrsus maximus; c. Close up of the colonies on the natural substrate; d. Conidiophores with head of conidia; e, f. Apically branched conidiophores with head of conidiogenous cells and conidia; g–j. Conidia; k, l. Colony on PDA from above and below. Scale bars: c, d = 100 µm, e, f = 50 µm, g–j = 10 µm.