Tuber tomentellum L. Fan & H.Y. Fu, 2023

Fu, Hao-Yu & Fan, Li, 2023, Tuber melanorufum and T. tomentellum, two new truffle species from China, Phytotaxa 594 (3), pp. 178-190 : 186-187

Tuber tomentellum L. Fan & H.Y. Fu sp. nov.

( FIG. 3 )

MycoBank:—MB 846498

Diagnosis:—differed from other species by the large ascospores reaching 78.55 μm in length and the numerous hyphoid or seta-like hairs on the peridial surface of ascomata.

Etymology:— tomentellum , tomemtose, referring to the ascomatal surface covered with short woolly hairs.

Typification: — CHINA. Yunnan Province: Kunming City , in soil under a Pinus forest, Oct 2020, collected by Jinzhong Cao ( BJTC FAN1340 )

Description:— Ascomata 1.3–2.2 cm, yellow brown (#f4d28d) to grey brown (#654321), surface even and finely tomemtose, with an indistinctly basal depression. Odor mild, flavour not recorded. Gleba brown (#7c2f20) at maturity, marbled with large and rare white veins.

Peridium 200–300 μm thick, two-layered: outer layer 150–200 μm thick, pseudoparenchymatous, composed of subglobose to irregularly shaped cells of 7.5–32.5 × 5–25 μm, thin-walled, light brown (#f5dbc2) toward outside surface; inner layer 75–150 μm thick, composed of interwoven hyphae 4–7.5 μm wide, hyaline, thin-walled, septate. Hairs arising from outermost cells of the peridium, two types, hyphoid, flexible, and having obtuse ends, or seta-like, erect, and having sharp ends, 30–90 × 2.5–4 μm, hyaline, slightly thick-walled, 1–3-septa. subglobose or ovoid, 80– 110 × 50–75 μm, hyaline, thin-walled, 1–3-spored, sessile. Ascospores ellipsoid to broadly ellipsoid, brown (#a52a2a) at maturity, reticulate, negative in Melzer’s reagent, excluding ornamentation, in 1-spored asci 30–78.5 × 25.7–46 μm, Q = 1.07–1.96 (Qm =1.52 ± 0.45) (n = 30), in 2-spored asci 31.1–64.5 × 26.2–41.4 μm, Q = 1.1–1.75 (Qm =1.43 ± 0.33) (n = 30), in 3-spored asci 29.6–62 × 24.2–38.9 μm, Q = 1.07–1.76 (Qm = 1.42 ± 0.35) (n = 30), reticulum 4–6 μm high, 6–7 meshes across spore width.

Habit, habitat and distribution: —hypogeous, gregarious, in soil under a Pinus forest in Yunnan Province, China. Currently, only known from China.

Additional specimens examined: — CHINA. Yunnan Province: Dali City, Xiangyun County, in soil under forest of Pinus sp. , 21 Oct 2020, Collected by Baoxiang Shi (BITC FAN1330); Kunming City, in soil under a Pinus forest, Oct 2020, collected by Baoxiang Shi (BJTC FAN1346).

Figures

FIGURE 3. Tuber tomentellum. a. Ascomata (BJTC FAN1340, holotype). b. SEM of ascospore. c, d, e. Light micrographs of asci and ascospores. f. Light micrograph of hyphoid hairs and the out layer of peridium. Scale bars: a = 1 cm, b = 10 μm, c, d, e = 50 μm, f = 100 μm. Photos by: Li Fan.