Botryosphaeriales » Botryosphaeriaceae » Dothiorella

Dothiorella septata

Dothiorella septata N. Wu, A.J. Dissanayake & Jian K. Liu, sp. nov.

Index Fungorum number: IF900580; Facesoffungi number: FoF14260.

Etymology: The epithet “septata” refers to the septum observed in mature conidia.

Holotype: MFLU 23-0007.

Saprobic on an unidentified dead wood. Sexual morph: Not observed. Asexual morph: Conidiomata 114–139 × 150–198 μm (x̅ = 126 × 172 μm, n = 20), pyriform or subglobose, immersing through the host epidermis, unilocular, glabrous, thick-walled, ostiolate. Ostiole 19–25 μm diam., single, straight, centrally located. Peridium up to 16–303 μm wide, with outer 3–5 layers of brown cells of textura angularis and inner 1–2 layers of hyaline cells of textura angularis. Paraphyses absent. Conidiophores are reduced to conidiogenous cells. Conidiogenous cells 5–10 × 2–5 μm (x̅ = 7 × 3 μm, n = 20), hyaline, phialidic, subcylindrical, smooth-walled. Conidia 19–21 × 8–10 μm (x̅ = 21 × 9 μm, n = 50), oblong to ovoid with a broadly rounded apex, initially hyaline to yellowish and aseptate, becoming brown to dark brown and one septate at maturation, slightly constricted at the septum, smooth-walled, without a mucilaginous sheath.

Culture characteristics: Conidia germinating on PDA within 12 h. Colonies are fast growing on PDA, reaching 90 mm diam. after 5–6 days at 20–23 °C. Sparse, aerial, filamentous, smooth with a crenate edge, white in first few days, becoming grey after one week, and after 2 weeks, becoming black.

Material examined: Thailand, Chiang Mai Province, Amphoe Mae Taeng, Tambon Sop Poeng, 19°07’52.3’’ N, 98°45’35.7’’ E, on an unidentified dead wood, 9 August 2019, Na Wu, YW173 (MFLU 23-0007, holotype); ex-type living culture MFLUCC 23-0039; ibid., on a decaying wood in a mountain, 7 August 2019, Na Wu, YW217 (GZAAS 23-0587, paratype), living culture GZCC 23-0583; ibid., YW228 (GZAAS 23-0588, paratype), living culture GZCC 23-0584.

Notes: The phylogenetic results showed that our isolates clustered with Do. ovata and formed a sister group. A comparison of ITS and tef1-α nucleotides shows that Do. septata is significantly different from its sister species, Do. ovata by 7/569 bp (1.2%) in ITS and 13/303 bp (4.3%) in tef1-α. In the phylogenetic analysis, these two species formed two distinct clades in Dothiorella. Morphologically, there are several differences in conidial morphology between these two species. Considering the morpho-molecular data, we introduced Do. septata as a new species.

Figure 1. Dothiorella septata (MFLU 23-0007, holotype). (a–c) Conidiomata on host substrate. (d) Vertical section of conidiomata. (e) Section of peridium. (f) Ostiolar region with periphyses. (g–k) Conidiogenous cells and developing conidia. (l–o) Conidia. (p) Germinated conidium. (q–s) Colonies on PDA, above (q,r) and below (s). Scale bars: (b) = 50 μm, (c,d) = 20 μm, (e–p) = 10 μm.

 

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