Bimuria omanensis Wijesinghe, Wanas., Al-Sadi, K.D. Hyde & Maharachch., 2020

Wijesinghe, Subodini N., Wanasinghe, Dhanushka N., Maharachchikumbura, Sajeewa S. N., Wang, Yong, Al-Sadi, Abdullah M. & Hyde, Kevin D., 2020, Bimuria omanensis sp. nov. (Didymosphaeriaceae, Pleosporales) from Oman, Phytotaxa 449 (2), pp. 97-108 : 104

Bimuria omanensis Wijesinghe, Wanas., Al-Sadi, K.D. Hyde & Maharachch. , sp. nov.

Index Fungorum number: IF557436; Facesoffungi number: FoF 07928; FIGURE 2 .

Etymology:—Name reflects the county Oman, from where the species was isolated.

Holotype:— SQU H-115

Asexual morph: Coelomycetous. Conidiomata pycnidial, arise on mycelia as black spore mass, aggregated clusters are scattered, irregular and superficial to semi-immersed. Conidiomatal wall composed of thick-walled, pale to dark brown cells of textura angularis. Conidiogenous cells 8–9 × 7–8 µm (x̄ = 8.36 × 7.6 µm, n=10), enteroblastic, phialidic, ampulliform or short cylindrical, determinate, sometimes cylindrical, with elongate neck, rough and hyaline. Conidia 7–10 × 3–4.5 µm (x̄ = 8.84 × 3.94 µm, n = 25) oblong to cylindrical, 1- septate, smooth and thin walled, hyaline to pale brown.

Culture characteristics:—Colonies on PDA reaching 60 mm diam. after 14 days at 24 °C, dark grey to brown in upper surface.

Known distribution:— Oman (this study)

Material examined:— OMAN, The Jebel Akhdar , Dakhiliyah Governorat, on decaying leaves of unidentified plant, July 2016, SSN Maharachchikumbura OM09 ( SQU H-115 , holotype) , ex-type living culture SQUCC 15280 .

Gene sequence data: ITS ( MT274326 ), LSU ( MT271820 ), TEF-1α ( MT279046 )

Notes:—In our DNA sequence analysis, Bimuria novae-zelandiae (CBS 107.79) and B. omanensis (SQUCC 15280) are monophyletic with strong bootstrap support ( Fig. 1 ). Morphological comparison between these taxa are currently impossible as B. novae-zelandiae is known from its sexual morph and only the asexual morph is known for B. omanensis . Comparison of the 570 ITS (+ 5.8S) nucleotides of these strains reveals 70 (12.3%) nucleotide differences. This could be due to ITS polymorphisms ( Stadler et al. 2020) and it is not surprising that these strains appear to belong to the same species. A comparison of the 852 nucleotides across the TEF-1α region revealed 32 bp (3.75%) differences between these strains suggesting these are distinct species ( Jeewon & Hyde 2016). Bimuria novae-zelandiae was isolated from soil of a barley field in New Zealand (Hawksworth et al. 1979). Bimuria omanensis was collected from a decaying leaf of a desert shrub in Ad Dakhiliyah Governorate, Oman. Therefore, based on the molecular data and habitat differences, we conclude that these two taxa are distinct species. Didymosporina aceris , Gordonomyces mucovaginatus and Lichenodiplis lecanorae share similar conidial morphology to Bimuria omanensis ( Wijayawardene et al. 2016) . Phylogenetically Gordonomyces mucovaginatus and Lichenodiplis lecanorae are not closely related to Bimuria omanensis (data not shown) and sequence data are unavailable for Didymosporina aceris .

Figures

FIGURE 1. RAxML tree based on analysis of a combined dataset of LSU, ITS and TEF1-α partial sequence data. Bootstrap support values for ML and MP equal to or greater than 60 %, Bayesian posterior probabilities (PP) equal to or greater than 0.95 are defined as ML/PP/MP above the nodes. Genera, where known are indicated with coloured blocks. The new isolate is in blue. The type strains are in bold. The scale bar represents the expected number of nucleotide substitutions per site. Bambusistroma didymosporum (MFLU 15-0057, MFLU 15-0058) is used as the outgroup taxon.

FIGURE 2. Bimuria omanensis (SQU H-115, Holotype) a. Hyphae. b–c. Sporulating conidiomata in culture media d. Conidioma wall. e–i. Conidiogenous cells. j–n. Conidia. Scale bars: d = 20 μm, h–i = 10 μm, e–g, j–n = 5 μm.