Hydnoporia subtabacina M. Cho, Y. Cho, Y. W. Lim & J. J. Kim, 2024

Cho, Minseo, Cho, Yoonhee, Kwon, Sun Lul, Kim, Dohye, Hosaka, Kentaro, Lim, Young Woon & Kim, Jae-Jin, 2024, Taxonomic study of Hydnoporia (Hymenochaetales, Hymenochaetaceae) in East Asia with two new species, MycoKeys 111, pp. 1-20 : 1-20

Hydnoporia subtabacina M. Cho, Y. Cho, Y. W. Lim & J. J. Kim sp. nov.

Fig. 4

Diagnosis.

Effused-reflexed, pileate basidiome, smooth, brown hymenial surface, sterile margin; cylindrical basidia with 14.6–17.9 × 2.9–3.8 μm, sharp-pointed and few elongated setae with 58.6–140.0 × 9.8–26.1 μm, narrowly cylindrical basidiospores with 4.4–5.7 × 1.6–1.9 μm, and occurs on angiosperm trees (branches and trunks).

Type.

Korea • Gyeongsangbuk-do, Bonghwa-gun, Taebaeksan National Park, Baekcheon valley , 37°00.64'N, 128°98.41'E, alt. 830 m, 22 Mar 2019, Y. W. Lim & S. Yoo, (holotype: NIBRFG 0000505378 ; isotype: SFC 20190322-02 ) .

Description.

Basidiome effused-reflexed, pileate, 0.1 mm thick. Hymenial surface smooth, membranaceous, brown (7.5 YR, 5 / 4) to dark brown (7.5 YR, 3 / 3). Margin sterile, slightly lighter. Hyphal system dimitic; generative hyphae septate, frequently branched, without a clamp connection, thick-walled, hyaline, 2.3–3.8 μm. Skeletal hyphae aseptate, unbranched, without a clamp connection, thick-walled, reddish-yellow (5 YR, 7 / 8) to yellow (10 YR, 7 / 8), 3.0–5.0 μm.

Basidia cylindrical, 4 - spored, smooth, thin-walled, hyaline, (14.0 –) 14.6–17.9 (– 18.7) × 2.9–3.8 μm. Setae sharp-pointed, encrusted with crystals, cylindrical, fusiform, few elongated apex, smooth, bearing a narrow or wide lumen, thick-walled, dark reddish brown (5 YR, 3 / 4) to dusky red (2.5 YR, 3 / 2), 58.6–140.0 × 9.8–26.1 μm. Basidiospores narrowly cylindrical, smooth, slightly curved, thin-walled, hyaline, with narrow apex, 4.4–5.7 × 1.6–1.9 μm, L = 5.22 μm, W = 1.68 μm, Q = 2.78–3.61, n = 21.

Distribution.

Korea, China, Far East Russia, and US.

Ecology.

Grew on Quercus in angiosperm forest.

Etymology.

Named after its morphological similarity with Hydnoporia tabacina .

Additional specimens examined.

Korea • Gangwon-do, Taebaek-si, Taebaeksan National Park, Yuilsa Temple , 37°10.87'N, 128°91.07'E, alt. 1,250 m, 10 May 2019, Y. W. Lim & S. Yoo, SFC 20190510-01 .

Notes.

According to our phylogenetic analysis, sequences annotated as ‘ Hyd. tabacina ’ were divided into a European and an Asian-North American clade (Fig. 2 ). The holotype specimen sequence is unavailable, but it is known that the specimen (≡ Aricularia tabacina Sowerby ) locality is Britain ( Sowerby 1797) and the lectotype specimen is from Sweden ( Miettinen et al. 2019). Therefore, we acknowledge the European clade ( Finland, Great Britain, and Western Russia) as Hyd. tabacina and the Asian-American clade ( China, Fareast Russia, Korea, and the US) as the new species, following the results of a previous study ( Miettinen et al. 2019). Hydnoporia subtabacina sp. nov. occurs only on angiosperm branches or trunks. The microscopic characteristics of Hyd. subtabacina and Hyd. tabacina are similar, but longer and wider basidiospores are reported in the latter species, viz. 4.58–5.9 × 1.78–2.02 μm ( Miettinen et al. 2019). Further, setal measurements of our specimens had broader variation (58.6–140.0 × 9.8–26.1 μm) compared to those of the Fareast Russian (63.92–94.15 × 9.38–14.5 μm) and North American specimens (71.1–97.9 × 9.5–14.23 μm) ( Miettinen et al. 2019). While there is a morphological description of Chinese ‘ Hyd. tabacina ’, no sequence data were available for these observed specimens ( Dai 2010). Additionally, the morphological characteristics of the Chinese ‘ Hyd. tabacina ’ with a hydnoid and yellowish basidiome ( Dai 2010) differ from those of the European specimens and of Hyd. subtabacina . Therefore, further research is needed for an accurate identification of Chinese ‘ Hyd. tabacina ’.

Figures

Figure 2. BI tree based on the ITS and tef 1 concatenated sequence datasets. The node numbers indicate the posterior probabilities (PP) above 0.7. Hydnoporia specimens examined in this study are shown in bold. Newly generated sequences in this study are shown in blue and bold. Porodaedalea alpicola (Cui 12280) is used as an outgroup. Letter codes after specimen voucher indicate ISO 3166 country code followed by the origin province. Detailed information is in Table 1. Type specimens are indicated with “ T ”.

Figure 4. Morphological characteristics of Hydnoporia subtabacina (NIBRFG 0000505378, holotype) A basidiome B microscopic features, s basidiospores; b 1 basidia; b 2 basidioles; h 1 generative hyphae; h 2 skeletal hyphae; se setae. Scale bars: 10 μm (s, b 1, b 2, h 1, h 2); 20 μm (se).