Tuber anniae W. Colgan & Trappe

Paez, Carolina Pina, Bonito, Gregory M., Guevara-Guerrero, Gonzalo, Castellano, Michael A., Garibay-Orijel, Roberto, Trappe, James M. & Ramirez, Rafael Pena, 2018, Description and distribution of Tuberincognitum sp. nov. and Tuberanniae in the Transmexican Volcanic Belt, MycoKeys 41, pp. 17-27 : 20-22

Tuber anniae W. Colgan & Trappe Fig. 2 a–d

Description.

Ascomata subglobose to slightly irregular, 10-12 mm broad, white, cream, light brown when dry. Peridium thin, <0.2 mm, smooth to velvety, irregularly roughened, furrows with depressions continuing as canals into the gleba. Gleba solid, brown, marbled with white veins that emerge as depressions on the peridium. Odour and taste not recorded.

Peridium 85-140 μm thick; pellis a pseudoparenchyma, 40-65 μm thick, cells 6-18 μm broad, versiform, isodiametric, squared, rectangular or angular, hyaline to yellowish in KOH, thick walled (> 1.0 μm), dermatocystidia absent; subpellis 45-75 μm thick, of hyaline, septate, interwoven hyphae (textura epidermoidea), 4.0-5.5 µm broad, thin walled, <1 μm thick. Gleba of hyaline, interwoven, sinuous hyphae, 5.0-7.5 µm broad, constrained at the septum, 3.0-4.5 μm broad at the septa, thin-walled (<1.0 μm).

Ascospores subglobose; excluding their alveolate-reticulate ornamentation, 1-spored asci 40-50 × 30-46 μm (Q= 1.03-1.15), 2-spored 28-38 × 26-35 μm (Q = 1.05-1.13), 3-spored 26-33 × 24-30 μm (Q = 1.04-1.15), spore colour orange-yellowish in KOH; walls> 2 μm thick, yellow; reticulum with 5-6 aveolae across the spore surface; the alveolar walls 3-4.5 μm tall. Asci subglobose, 84-105 × 75-85 μm, pedicel lacking to prominent, walls with 2-3 layers, hyaline in KOH; hyphae around the asci interwoven, 3.5-5.5 μm broad at the septum, thin walled (<1.0 μm), hyaline in KOH.

Distribution and ecology.

Wang et al. (2013) reported from Europe; Colgan and Trappe 1997; Bonito et al. (2010) reported in North America. Here, we extended the distribution to central México (State of México and Tlaxcala). In Finland, T. anniae has been confirmed to establish association with P. sylvestris L. ( Wang et al. 2013). In Washington, this species has been confirmed to establish association with Pseudotsuga menziesii (Mirbel) Franco ( Bonito et al. 2010). In México, sporocarps always collected co-occurring with Pinus leiophylla Schiede and Deppe and Abies religiosa (Kuntch) Schldl. and Cham. In México, the only environmental DNA of this species has been recovered from soil in conifer forests in Tlaxcala associated with Pinus montezumae and in State of México associated with A. religiosa ( Argüelles-Moyao and Garibay-Orijel 2018).

Collections examined.

MÉXICO, State of Tlaxcala, Huamantla, cañada central, La Malinche National Park, under Pinus leiophylla Schiede and Deppe and Abies religiosa (Kunth) Schltdl. and Cham., hypogeous, solitary, 3220 m alt., 19°14'7"N, - 97°59'9"W, 23 September 2007, G.M. Bonito (OSC 157842), GB MH174660.

Taxonomic comments.

Tuber anniae is similar to Tuber pacificum Trappe, Castellano and Bushnell, however, the latter species has narrower, ellipsoid spores (23-15 × 16-35 μm) and a thicker peridium (250-400 μm) than the former. T. pacificum has also been found co-occurring with Pseudotsuga menziesii and Tsuga heterophylla (Raf.) Sarg. along costal Oregon, while T. anniae has been found co-occurring with P. leiophylla and A. religiosa .

Tuber anniae was first described by Colgan and Trappe (1997). The holotype (from Washington) and the other collections reported were from the Pacific Northwest in the US and reported co-occurring with P. menziesii . The T. anniae complex of species has been proposed based on phylogenetic analysis using ITS region ( Wang et al. 2013). The collection from México is very similar to the holotype collection, however, the latter has a brown to dark olive-brown peridium and its spores have thicker (up to 5 μm) spore walls than the former. Additionally, T. anniae , as described by Colgan and Trappe (1997), has mostly globose spores with 10-16 alveolae across the spores. The Finnish collections exhibit subtle morphological differences in comparison with the collections from North America. The Finnish specimens have a smooth peridial surface, except along the grooves and around the pits ( Wang et al. 2013), while the holotype specimen was reported to be smooth and lack dermatocystidia ( Colgan and Trappe 1997). It seems that the presence of dermatocystida only along the grooves and/or at the bottom of pits in Tuber collections is likely the result of handling of the ascoma during processing (Dr. D. Luoma, personal communication). Additionally, the spores from the Finnish specimens have larger dimensions (27-60 × 27-56 μm; Q = (1.00) 1.05-1.20 (1.33)) than the specimens described for T. anniae by Colgan and Trappe from Washington (1997).