Rhytidhysteron tectonae

Rhytidhysteron tectonae Doilom & K.D. Hyde 2016

Index Fungorum number: IF 551964

Saprobic on decaying wood. Sexual morph Hysterothecia 550–950 µm long, 450–600 µm high, 400–500 diam. (x̅ = 800 × 500 × 450 µm, n = 5), semi-immersed to superficial, scattered, apothecial, erumpent from the substrate, dark brown to black, coriaceous, elongate with a longitudinal slit. Exciple 70–110 µm (x̅ = 90 µm, n = 15), thick-walled, composed of brown to dark brown cells of textura globulosa to angularis. Hamathecium comprising 1–2 μm wide, numerous, septate, branched, pseudoparaphyses. Asci 170–200 × 10–12 μm (x̅ = 190 × 11, n = 15), 8-spored, bitunicate, cylindrical, with short pedicel, rounded at the apex, with an ocular chamber. Ascospores 25–29 × 8–10 µm (x̅ = 27 × 9 µm, n = 20), uniseriate, hyaline to brown, 1–3-septate, smooth-walled, ellipsoidal to fusoid, straight or curved, rounded to slightly pointed at both ends, guttulate. Asexual morph Undetermined.

Material Examined: Thailand, Chiang Rai Province, Mae Yao District, on dead woody twigs of Betula sp. (Betulaceae), 23-Sep-2019, G.C. Ren, MY09 (HKAS 115533), living culture MFLUCC 21-0037; Thailand, Chiang Rai Province, Mae Fah Luang University, on dead woody twigs of Fabaceae, 5-Jul-2019, G.C. Ren, RMFLU19001 (HKAS 115532), living culture MFLUCC 21-0034.

Notes: Rhytidhysteron tectonae was introduced by Doilom et al. (2016) based on morphological and phylogenetic analyses from dead branches of Tectona grandis in Thailand. Based on our phylogenetic analysis of the combined SSU, LSU, ITS, and tef1-α sequence data, our collections (MFLUCC 21-0034 and MFLUCC 21-0037) cluster with the strain of R. tectonae (MFLUCC 13-0710) with 85% ML, 92% MP, 1.00 PP bootstrap support. Our collection shares similar morphological features with R. tectonae (MFLU 14-0607). However, our new collection has smaller hysterothecia (800 × 500 × 450 μm vs 2175 × 585 × 523 μm) and longer asci (190 μm vs 155 μm) in comparison to the type. Based on morphological characteristics and phylogenetic analysis, we introduce MFLUCC 21-0034 and MFLUCC 21-0037 as new host records of R. tectonae from decaying wood of Betula sp. and Fabaceae sp. in Thailand.