Tatraea griseoturcoisina C.J.Y. Li & Q. Zhao, 2024

Li, Cui-Jin-Yi, Thilini Chethana, Kandawatte Wedaralalage, Eungwanichayapant, Prapassorn Damrongkool, Zhou, De-Qun & Zhao, Qi, 2024, Additional four species of Tatraea (Leotiomycetes, Helotiales) in Yunnan Province, China, MycoKeys 102, pp. 127-154 : 127

Tatraea griseoturcoisina C.J.Y. Li & Q. Zhao sp. nov.

Fig. 6

Etymology.

The specific epithet refers to the greyish turquoise color of the disc.

Holotype.

HKAS 128276.

Description.

Saprobic on decayed branches. Sexual morph: Apothecia 2.5-4.0 mm wide (x̄ = 3.1 ± 0.4 mm, n = 27) when fresh, 1.0-2.1 mm wide × 0.6-0.8 mm high (x̄ = 1.6 ± 0.3 × 0.7 ± 0.1 mm, n = 20) when dry, scattered or gregarious, superficial, discoid with thin and short stipitate, glabrous. Disc flat and circular, greyish turquoise (24E5) when fresh in wet habitat, slightly concave in the center, edge slightly curved upwards, deep green (28E8) with greyish green (28D5) to dark greyish green (28F7) when fresh in slightly dried habitat, edge slightly fold inward towards the discs, yellowish white (1A2) to snow white (1A1) when dry. Margins concolorous to the discs when fresh in wet habitat, white when dry or living in the dried habitat. Receptacle not observed when fresh, rough and finely pustules, dark brown to nearly black when dry, with some slightly dark and irregular veins on the surface. Stipe 330-360 μm wide × 220-440 μm long (x̄ = 350 ± 89 × 330 ± 8 μm, n = 5), short and thin, rough and finely pustules, concolorous to the receptacle. Hymenium 103-138 μm (x̄ = 117 ± 8 μm, n = 25), hyaline. Subhymenium 43-66 μm (x̄ = 53 ± 6 μm, n = 15), dense brownish-orange (6C8) hyphae of textura intricata, hyphae 1.3-2.9(-3.9) μm (x̄ = 2.2 ± 0.5 μm, n = 50) diam., appear with excipulum at the margin, non-gelatinous. Medullary excipulum 164-308 μm (x̄ = 238 ± 33 μm, n = 15) thick, well-developed, comprised of thin-walled, septate, pale brown to pale yellow cells of textura intricata, hyphae 2.6-5.2 μm (x̄ = 3.9 ± 0.5 μm, n = 30) diam., hyaline, slightly loose in the center, becoming well-organized, parallel and strongly dense near the ectal excipulum, narrow hyphae 1.3-3.2 μm (x̄ = 2.3 ± 0.4 μm, n = 30) diam., non-gelatinous. Ectal excipulum well-differentiated from the medullary part, the inner layers generally consists of 5-6 layers textura angularis cells, 27-68 μm (x̄ = 42 ± 9 μm, n = 37) thick, cells 6.6-14.4 μm (x̄ = 10.2 ± 2.4 μm, n = 100) diam., wall moderately thick 0.41-0.84 μm (x̄ = 0.6 ± 0.1 μm, n = 50); the outer layers partially uneven proliferous to some gradually smaller brown cells, stack into short and broad triangles to trapezoids, 20-46(-63) μm (x̄ = 31 ± 12 μm, n = 20) thick (excluding the inner layers), cells 4.5-10.2 μm (x̄ = 7.8 ± 1.6 μm, n = 80) diam., wall moderate; cells from the outer inward the inner layers gradually increase in diameter, brown to pale yellow; terminal cells at the margin stretch to elongated textura prismatica cells 10-13 μm × 3.3-4.1 μm with rounded ends, wall moderately thick, brown, non-gelatinous. Paraphyses 1.7-2.7 μm (x̄ = 2.3 ± 0.2 μm, n = 35), hyaline, filiform, rounded apex, 2-septate at the middle, unbranched, conspicuous contents not observed, scarcely extending beyond the asci. Asci (91-)109-122 × 8.2-11.5 μm (x̄ = 113 ± 5 × 9.5 ± 0.7 μm, n = 25), unitunicate, 8-spored, almost filling the whole asci, clavate, rounded apex with an amyloid apical pore in Melzer’s reagent, wall incrassated at the apex, 5.5-6.8 μm wide × 2.3-4.2 μm high (x̄ = 6.0 ± 0.5 × 3.2 ± 0.4 μm, n = 25), slightly constricted downward when developing, tapering to a cylindric and aporhynchous subtruncate base, croziers present. Ascospore 14.6-20.4(-22.5) × 4.9-6.2 μm (x̄ = 17.1 ± 1.7 × 5.4 ± 0.4 μm, n = 60), Q = 2.4-3.7(-4.2), Qm = 3.1 ± 0.1, overlapping uniseriate, slightly narrow ellipsoidal with a large guttule, ends rounded at the base, slightly pointed at the apex, slightly curved on the lateral view, hyaline, thin-walled, smooth and aseptate. Asexual morph: Undetermined.

Material examined.

China, Yunnan Province, Xishuangbanna City, Menghai County, altitude 1660 m, on decayed oak tree branches in a managed plantation, 8 September 2022, Cuijinyi Li , LCJY-1402 (HKAS 128276, holotype); ibid., Menghai County , altitude 1500 m, on decayed oak tree branches in a managed plantation, 8 September 2022, Cuijinyi Li, 22-9-8-5 (HKAS 128277, paratype) .

Notes.

The distinctive characteristics of Tatraea griseoturcoisina are greyish-green apothecia, with yellowish-white to snow white discs when dry, narrow hyphae of medullary excipulum, short aporhynchous asci and slightly narrow ellipsoidal ascospores without septa.

Phylogenetically, T. griseoturcoisina grouped with T. clepsydriformis with 85% ML bootstrap support and 0.96 Bayesian probability in the combined LSU and ITS phylogeny (Fig. 2 ). A pairwise homoplasy index (PHI) test was conducted using a five-gene dataset (ITS, LSU, mtSSU, RPB1 and RPB2) to assess the recombination level between clades of T. griseoturcoisina and T. clepsydriformis . The results revealed that there were no significant recombination events observed between these two groups ( Фw > 0.05), indicating that they are genetically isolated and thus supporting them as distinct species (Fig. 3 ). Tatraea griseoturcoisina is distinct from all other species based on its unique macro-characteristics of greyish-green apothecia, dried discs and receptacles. Micro-characteristics of T. griseoturcoisina resemble T. clepsydriformis by having narrow hyphae of medullary excipulum, short asci and smaller ellipsoidal ascospores, but it is distinct from T. clepsydriformis by having a thinner medullary excipulum (164-308 μm vs. 335-535 μm), longer (17.1 × 5.4 μm vs. 15.2 × 5.7 μm) and curved ascospores. Tatraea griseoturcoisina can be distinguished from the other five species ( T. aseptata , T. dumbirensis , T. macrospora , T. yunnanensis and T. yuxiensis ) based on its short asci (109-122 μm) and ascospores (14.6-20.4 μm) (see Suppl. material 1).

Figures

Figure 2. Maximum likelihood tree based on a combined dataset of LSU and ITS sequences for the genus Tatraea. The ML bootstrap proportions (ML-BP) equal to or higher than 70 % and Bayesian posterior proportions (BI-PP) equal to or higher than 0.90 are shown near the branches on the phylogenetic tree. Newly generated isolates of the current study are shown in blue and ex-types are shown in bold.

Figure 3. The results of the pairwise homoplasy index (PHI) test for the closely related species in Tatraea using LogDet transformation. A. PHI test for Tatraea yunnanensis vs. Tatraea macrospora. B. PHI test for Tatraea yuxiensis vs. Tatraea aseptata. C. PHI test for T atraea Tatraea clepsydriformis vs. Tatraea griseoturcoisina. PHI test results (Φw <0.05) indicate significant recombination within the dataset.

Figure 6. Tatraea griseoturcoisina (HKAS 128276, holotype) a fresh ascomata on the wood d-g dried ascomata on the wood d vertical section of an ascoma e-h excipulum i paraphyses j-n asci (o-n asci in Meltzer's reagent) o-t ascospores. Scale bars: 900 μm (b); 600 μm (c); 1000 μm (d); 80 μm (e, g); 40 μm (f); 60 μm (h-n); 10 μm (o-t).