Tuber melanoexcavatum 2020

Tuber melanoexcavatum Y. Wang & S.H. Li, sp. Nov. 2020

MycoBank MB 818925

Holotype: CHINA, Yunnan, Hua-ning County, 24°15′34′′N 102°55′11′′E, alt. 1900 m, in forest of C. glaucoides, Shuhong Li, 9 January 2015 (YAAS L3605, holotype), GenBank number: ITS, KY081684; Huaning County, 24°15′31′′N 100°55′11′′E, alt. 1800 m, Shuhong Li, 10 January 2015, YAAS L3636; Hua-ning County, 24°15′30′′N 102°55′09′′E, alt. 2200 m, Shuhong Li, 9 January 2015,YAAS L3968; China, Yunnan province, Hua-ning County, 24°15′31′′N 102°55′11′′E, alt. 1925 m, Shuhong Li, 9 December 2015, YAAS L3984.

Morphological description

Ascomata hypogeous, globose to subglobose, up to 6 cm diameter, with a conspicuous basal cavity, black at maturity, covered with pyramidal warts, 4–6 sided, 2.5–4 mm across, up to 2 mm high, apex pointed. Peridium thickness variable, commonly 160–270 μm thick, composed of two layers, the outer layer 80–107 μm thick, pseudoparenchymatous, composed of subglobose to subangular, pale yellow or hyaline cells of 7.1–10.5 × 6–9.9 μm in diameter, with thickened dark brown walls, and the inner layer 80–100 μm thick, composed of interwoven, hyaline to brownish hyphae of 2–4 μm in diameter. Gleba greyish-brown at maturity, marbled with white meandering veins. Asci 60.2–64 × 54.4–56.5 μm, commonly 5–8-spored, globose to subglobose or ellipsoid, sessile, with thin or slightly thickened walls. Ascospores in 5-spored asci 22–24.7 × 15.4–16.9 μm, 6-spored asci 21.4–24 × 14.3–16.0μm, 7-spored asci 20–22 × 13.5–15.5 μm; 8-spored asci 18.7–21.2 × 12.6–15.1 μm (excluding ornamentation) ellipsoid, sometimes subellipsoid, hyaline when young, becoming yellowish brown at maturity; Q = 1.19, spino-reticulate, 3–4 μm tall. 

Habitat: in forest of C. glaucoides 

Distribution: Yunnan, China.

GenBank Accession: KY081684, KY081685, KY081686, KY081687

Notes: 

Reference: LI WANG^1,2,3,6, SONG-MING TANG^1,3,7, XIAOLEI ZHANG^2,8 et al.

Black truffle species from China. a. T. melanoexcavatum (YAAS L3605, holotype). b. An ascus with 8 ascospores of T. melanoexcavatum.