Ginnsia laricicola Xue W. Wang & L.W. Zhou, sp. nov.
Index Fungorum number: IF 900285; Mycobank number: MB 900285; Facesoffungi number: FoF 14049; Figs. 1, 2
Etymology – laricicola (Lat.) referring to the host genus Larix.
Holotype – LWZ 20180830–9 (HMAS).
Diagnosis – Characterized by annual resupinate basidiomes, byssoid to fibrillose subiculum, cinnamon to yellowish brown hymenophore, a monomitic hyphal system with densely encrusted subicular hyphae, cylindrical cystidia, clavate basidia, and ellipsoid to broadly ellipsoid basidiospores.
Basidiomes resupinate, annual, flaking easily off subiculum when dry. Subiculum byssoid to fibrillose. Hymenophore smooth, cinnamon to yellowish brown; margin abrupt, concolorous with subiculum.
Hyphal system monomitic; generative hyphae hyaline, thin-walled, simple septate. Subicular hyphae hyaline, thinwalled, frequently branched, simple septate, interwoven, densely encrusted, 3.5–4 µm in diam. Subhymenium thin, poorly delimited from context. Cystidia cylindrical with obtuse apex, thin- to slightly thick-walled, 60–90×9–10 µm. Basidia clavate with stalked bases, thin-walled, simple septate with four sterigmata, guttulate, 20–30× 8.5–9.5 µm; basidioles in shape similar to basidia but slightly smaller. Hyphidia hyaline, thin-walled, smooth, usually branched, 2.5–3.5 µm in diam. Basidiospores ellipsoid to broadly ellipsoid, with blunt apex, hyaline, thin-walled, guttulate, IKI−, CB−, (8.5–)9–9.5×5–6 µm, L=9.29 µm, W =5.52 µm, Q=1.66–1.68 (n=90/3).
Material examined – China, Shaanxi Province, Baoji, Mei County, Taibai Mountain, on stump of Larix, 30 August 2018, L.W. Zhou, LWZ 20180830–9 (HMAS, holotype); ibid., LWZ 20180830–5 (HMAS), LWZ 20180830–6 (HMAS).
GenBank numbers – LWZ 20180830–5: ITS=OQ540881; LSU = OQ540842; LWZ 20180830–6: ITS= OQ540882; LSU = OQ540843; LWZ 20180830–9: ITS= OQ540883; LSU=OQ540844.
Notes – Ginnsia laricicola resembles the generic type G. viticola; however, G. viticola differs in its slightly longer cystidia (60–125 µm) and basidia (25–50 µm, Burdsall 1985). Moreover, G. laricicola was only found on Larix, while G. viticola has a wider host range. Phylogenetically, two vouchers labeled as G. viticola are separated from each other (Fig. 3), which indicates that the concept of G. viticola may be a species complex and needs to be further clarified.
Figure 1 – Basidiomes of Ginnsia laricicola (LWZ 20180830–9, holotype)
Figure 2 – Microscopic structures of Ginnsia laricicola (LWZ 20180830–9, holotype). a Basidiospores. b Basidia and basidioles. c Cystidia. d Hyphidia. e Subicular hyphae. Scale bars: a–e =10 μm
Figure 3 – Phylogram generated by the maximum likelihood algorithm based on combined nLSU and ITS sequence data is presented along with the bootstrap values and the Bayesian posterior probabilities above 50% and 0.8, respectively, at the nodes. Type specimens are in bold and the isolates of new species characterized are in blue