Boeremia wisteriae Jayasiri & K.D. Hyde, sp. nov.
Index Fungorum number: IF 556935; MycoBank number: MB 556935; Facesoffungi number: FoF 07391; Fig. 1
Etymology – based on the host genus that specimen was collected.
Saprobic on decaying pod of Wisteria sp. Sexual morph: Undetermined. Asexual morph: Conidiomata 155–225 high×186–220 μm diam. (x=187×196 μm, n=20), pycnidial, mostly globose to subglobose, glabrous or with few mycelial outgrowths, superficial on agar surface or immersed, solitary or confluent. Ostioles indistinct papillate, internal wall covered with hyaline filiform cells when mature. Pycnidial wall 32–53 μm wide, pseudoparenchymatous, Ellipsoid, globose, oblong to allantoid. Conidiogenous cells 3–7.5×3–6.5 μm. (x=5.5×4.5 μm, n=20), ampulliform to doliiform, phialidic, hyaline, simple, smooth. Conidia 6–8×2–4 μm (x=6.8×3.5 μm, n=20), ellipsoid, globose, oblong to allantoid, hyaline, thin-walled, smooth, aseptate,
polar biguttulate.
Culture characteristics – Conidia germinating on MEA within 24 h. Germ tubes produced from ends of conidia. Colonies circular, flat, filiform margin, cottony, pinkish white, light brown to grey, lower surface off white to pale brown, reaching 40–50 mm diam. in 14 days at 18 °C. Mycelia are superficial, effuse and radially striate with regular edge. Sporulation observed after 30 days under 18 °C.
Material examined – China, Yunnan Province, Kunming City, garden of Kunming Institute of Botany, decaying pod of Wisteria sp., (Fabaceae), 25 May 2018, Jayasiri S.C., C 455 (MFLU 18-2209, holotype; KUN-HKAS 102439, isotype), ex-type culture, MFLUCC 18-1562.
GenBank numbers – ITS: MK347804, LSU: MK348023, tef1-α: OQ304686, β-tubulin: OQ304687, rpb2: OQ304685, SSU: MK347912
Notes – Our isolate (MFLUCC 18-1562) groups with Boeremia pseudolilacis (CBS 101207, CBS 462.67 and CBS 423.67) and B. rhapontica (CBS 113651) with week bootstrap support in our multigene phylogenetic analysis (Fig. 2). The pycnidial and conidial characters of our new strain fits with the Boeremia species (Aveskamp et al. 2010). The nucleotide differences of β-tubulin and rpb2 of our strain with B. rhapontica gives 0.84% and 1.34% and the nucleotide differences of β-tubulin and rpb2 of our strain with B. pseudolilacis (CBS 101207, CBS 423.67) gives 1.29% and 1.34% respectively. Morphologically, these three species are similar, but Boeremia pseudolilacis does not have clear morphological description with the measurements. Our new strain can be distinguished from B. rhapontica by the measurements of conidiomata and conidia (186–220 μm vs 50.3–199.1 μm diam. and 6–8×2–4 μm vs 3.6–7.1×1.7–3.9 μm) (Berner et al. 2015). Boeremia pseudolilacis identified from Syringa vulgaris, and Boeremia rhapontica as a pathogen on Rhaponticum repens, but our new strain has collected from decaying pod of Wisteria sp. Therefore, we introduce this collection as Boeremia wisteriae sp. nov.
Figure 1 – Boeremia wisteriae (MFLUCC 18-1562, ex-type). a Frontal view of the culture on MEA. b Reverse view of the culture on MEA. c, d Formation of conidiogenous cells. e, f Conidia. Scale bars: a, b=1 cm, c=10 µm, d–f=5 µm
Figure 2 – Simplified phylogram showing the best RAxML maximum likelihood tree obtained from the combined multi-gene (ITS, LSU, rpb2, and β-tubulin). The matrix comprises 2745 characters with gaps. The tree is rooted with Phoma herbarum (CBS 615.75). The best scoring RAxML tree with a final likelihood value of − 8211.587479 is presented. The matrix had 406 distinct alignment patterns, with 18.95% of undetermined characters or gaps. Estimated base frequencies were as follows; A=0.238114, C=0.240500, G=0.268943, T=0.252444; substitution rates AC=1.468423, AG=3.444817, AT=1.827506, CG=1.210667, CT=10.782158, GT=1.0. ML bootstrap support (first set) equal or greater than 70% and Bayesian posterior probabilities equal or greater than 0.95 are given near to each branch. The new isolate is in blue bold. The extype strains are in bold