Distoseptispora eleiodoxae O. Karimi, Q.R. Li & K.D. Hyde, 2024

Karimi, Omid, Chethana, K. W. Thilini, de Farias, Antonio R. G., Asghari, Raheleh, Kaewchai, Saithong, Hyde, Kevin D. & Li, Qirui, 2024, Morphology and multigene phylogeny reveal three new species of Distoseptispora (Distoseptisporales, Distoseptisporaceae) on palms (Arecaceae) from peatswamp areas in southern Thailand, MycoKeys 102, pp. 55-81 : 55

Distoseptispora eleiodoxae O. Karimi, Q.R. Li & K.D. Hyde sp. nov.

Fig. 3

Etymology.

The epithet " eleiodoxae " refers to the name of the host genus, Eleiodoxa conferta .

Holotype.

MFLU 23-0277.

Description.

Saprobic on submerged rachis of Eleiodoxa conferta in peatswamp forest. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Mycelium immersed to superfacial, septate, smooth, brown to dark brown. Colonies on submerged rachis, solitary, scattered, dark brown to black. Conidiophores 71-161 × 5-6.5 µm (x̄ = 110 × 5.7 µm, n = 20), macronematous, mononematous, cylindrical, erect, straight to flexuous, unbranched, smooth or finely verrucose, thick-walled, dark brown, 5-10-septate with lobed basal cells, percurrent proliferations at the apex. Conidiogenous cells 13.5-18.8 × 5-6.8 µm (x̄ = 15.96 × 5.6 µm, n = 20), holoblastic, monoblastic, terminal, integrated, cylindrical to ampulliform, percurrent, brown to dark brown, smooth. Conidia 31.5-48 × 13.5-15.8 µm (x̄ = 40.8 × 14.8 µm, n = 30), secession schizolytic, solitary, obpyriform, rostrate, truncated base, 6-7-euseptate, verrucose, thick-walled, brown with dark brown to black cells in the middle, paler towards the apex.

Culture characteristics.

Colonies grown on PDA, reaching 30 mm in diameter after 15 days at 25 °C, under dark conditions, circular, entire to radially with lobate edge, well-defined margin, low convex, dull surface, felted, dense, mycelium superficial to immersed, without pigment diffusion and sporulation, greyish-brown on the top with dark brown margin, reverse brown with dark brown centre and margin.

Material examined.

Thailand. Narathiwat Province: Yi-ngo District , peatswamp forest, on submerged rachis of Eleiodoxa conferta , 06 April 2022, Omid Karimi, S 5PP8N1SG (MFLU 23-0277, holotype); ex-type culture MFLUCC 23-0213, additional living culture MFLUCC 23-0214 .

Notes.

Distoseptispora eleiodoxae (MFLU 23-0277) shares similar characteristics with D. tropica J. Ma & Y.Z. Lu (HKAS 123761), in having macronematous, mononematous, cylindrical, erect, straight, unbranched conidiophores with holoblastic, monoblastic, terminal, cylindrical, thick-walled conidiogenous cells and verrucose, rostrate conidia ( Ma et al. 2022). However, D. eleiodoxae (MFLU 23-0277) differs from D. tropica (HKAS 123761) in having shorter and wider obpyriform conidia (31.5-48 × 13.5-15.8 µm vs. 39-75 × 7.5-10.5 µm), with broad and darker middle cells, no guttules and lacking conspicuous hyphae attachment to conidia. The BLAST search against GenBank showed that the ITS and LSU sequences of the new isolate, D. eleiodoxae (MFLUCC 23-0213), share 84.25% similarity across 100% sequence coverage with D. tropica (GZCC 22-0076) and 96.09% similarity across 100% sequence coverage with D. effusa L.L. Liu & Z.Y. Liu, respectively. Distoseptispora eleiodoxae (MFLU 23-0277) differs from D. effusa (GZAAS 20-0427) in having shorter conidia (31.5-48 vs. 35.5-113 µm) ( Yang et al. 2021). Based on a pairwise comparison of ITS, LSU, rpb2 and tef1-α nucleotides, D. eleiodoxae (MFLUCC 23-0213) differs from D. tropica (GZCC 22-0076) in 70/536 bp (13.05%) for ITS, 50/834 bp (5.99%) for LSU, 141/1052 bp (13.40%) for rpb2 and 96/888 bp (10.8%) for tef1-α (without including gaps). Therefore, we introduced D. eleiodoxae (MFLU 23-0277) as a novel species, based on the morphological evidence and according to the species delimitation guidelines proposed by Chethana et al. (2021) and Maharachchikumbura et al. (2021).

Figures

Figure 3. Distoseptispora eleiodoxae (MFLU 23 - 0277, holotype) a host material b, c colonies on the substrate d-f conidiophores and conidia g conidiogenous cell h-j conidia k culture on PDA (top and reverse). Scale bars: 100 µm (b, c); 30 µm (d-f); 10 µm (g-j).