Tuber himalayense B.C. Zhang & Minter, Trans. Br. Mycol. Soc.

Kinoshita, Akihiko, Nara, Kazuhide, Sasaki, Hiromi, Feng, Bang, Obase, Keisuke, Yang, Zhu L. & Yamanaka, Takashi, 2018, Using mating-type loci to improve taxonomy of the Tuber indicum complex, and discovery of a new species, T. longispinosum, PLoS ONE (e 0193745) 13 (3), pp. 1-21 : 12-15

Tuber himalayense B.C. Zhang & Minter, Trans. Br. Mycol. Soc. 91(4): 595 (1988).

MycoBank MB 134661. Fig 7A–7E = Tuber formosanum H.T. Hu & Y. Wang, Mycotaxon 123: 296 (2013).

MycoBank MB 563693

Etymology: Japanese name “ Asiakuroseiyoshoro ” from Asia = locality, Kuro = black, seiyoshoro = Japanese name for the genus Tuber ).

Ascomata: hypogeous, 20–60 mm in diam, subglobose and slightly lobed, firm, brown (10 R 4/8) to dark greyish (7.5YR 8/18), with low polygonal warts, 4–6 ridges, up to 500-μm high. Odor: aromatic, similar to seaweed or laver boiled in soy sauce when mature. Peridium: 400– 800 μm thick, variable, pseudoparenchymatous, composed of two layers: outer layer 150–

200 μm thick, composed of irregular or ellipsoidal cells 10–20 × 5–15 μm, with thick, dark brown 1–2-μm walls; inner layer 200–600-μm thick, composed of hyaline to yellowish, polygonal cells 5–15 × 5–10 μm that merge with glebal tissue of interwoven hyphae. Gleba: solid, whitish when young, becoming dark brown to blackish at maturity, marbled with distinct, whitish, meandering veins that merge at many points. Interwoven hyphae of glebal tissue:

3–7 μm broad with scattered cells, gelatinized, inflated up to 10 μm. Asci: typically subglobose to broadly ellipsoid, occasionally ellipsoid, variable depending on number of spores, 48–

81 × 38–73 μm (n = 164), rarely stipitate, 1–4(–5)-spored. Ascospore: mostly ellipsoid, rarely globose, whitish or hyaline when young, becoming light brown (5 Y 8/3) to dark brown (5YR9/ 4) at maturity, 31–41 × 24–35 μm, Q = 1.1–1.6 (1-spored, n = 7); 24–44 × 17–32 μm, Q = 1.0– 1.6 (2-spored, n = 22); 17–37 × 15–33 μm, Q = 1.0–1.8 (3-spored, n = 154); 14–34 × 12–26 μm, 1.0–2.0 (4-spored, n = 279); 18–31 × 14–22 μm, Q = 1.0–1.9 (5-spored, n = 24), excluding ornamentation. Ornamentation with very variable: spines with free, partial reticulate, spiny-reticulate, and alveolate. Spines up to 2–7 (9) μm (n = 508) in height with 3–7-μm bases.

Habitat and distribution: North-western Provinces of India to southern China, Taiwan and Japan. In Japan, the fruiting period is from July to January. Woodland under Betula and Carpinus ( Betulaceae ); Castanea , Castanopsis and Quercus ( Fagaceae ); and Abies and Pinus ( Pinaceae ).

Specimens examined: JAPAN: MIYAGI Prefecture, Sendai City, Dec 2003, collected by Yoko Ando, K 464 ( TFM: S 17011); Sendai City, 23 Oct 2005, collected by Yoko Ando, K 465 ( TFM: S 170012); CHIBA Prefecture, Narashino City, under Q. acutissima , 15 Nov 2015, collected by Hiromi Kinoshita, S 27 ( TFM: S 17013); KYOTO Prefecture, Kyoto City, under Q. glauca and Q. serrata , 6 Dec 2004, collected by Takashi Yamanaka and Keisuke Obase, S 4 ( TFM: S 17014); HYOGO Prefecture, Sanda City, under Q. glauca , 27 Nov 2015, collected by Mitsuo Nabe and Michiyo Nabe, S 17 ( TFM: S 17015); OKAYAMA Prefecture, Niimi City, under Carpinus tschonoskii and Q. serrata , 19 Dec 2015, collected by Hideo Hara, S 23 ( TFM: S 17016); KOCHI Prefecture, Umaji Village, under Q. glauca and Q. serrata , 3 Feb 2017, S 66 ( TFM: S 17017); EHIME Prefecture: Futami-cho, under Castanopsis sieboldii and Quercus sp. , 24 Nov 2006 collected by Fumitaka Nagao, K 152 ( TFM: S 17018); OITA Prefecture, Yufu City, 24 Oct 2008, collected by Atsuko Hadano and Eiji Hadano, K 307 ( TFM: S 17019); Yufu City, under Q. acutissima and Q. serrata , 8 Oct 2006, collected by Hiromi Sasaki, K 448 ( TFM: S 17020).

Additional comments: Hu [ 4] described T. formosanum from Taiwan as a distinct species based on morphological observation; subsequently, Qiao et al. [ 6] typified T. formosanum based on a newly collected sample, because there was no typification in the original description by Hu [ 4]. They denoted that T. formosanum differs from T. indicum by its asci with a short stipitate, spiny-reticulate ascospores and association with Cyclobalanopsis glauca (= Quercus glauca ) [ 6]. However, we showed that T. formosanum is phylogenetically and morphologically indistinguishable from T. himalayense (= T. indicum group B) and Tuber sp. 6 . Because T. himalayense was described by Zhang & Minter [ 7] before T. formosanum was described by Hu [ 4], we synonymize T. formosanum with T. himalayense (hereafter we call Tuber sp. 6 and T. formosanum as “ T. himalayense ”).

Figures

Fig 7. Tuber himalayense photographs (TFM: S17015). A. Ascomata (bar = 1 cm). B. Peridial warts, (bar = 3 mm). C. Asci and ascospores (bar = 30 μm). D. Peridium and glebal tissue in cross section (bar = 50 μm). E. Ascospore (bar = 10 μm). https://doi.org/10.1371/journal.pone.0193745.g007