Rhytidhysteron tectonae Doilom & K.D. Hyde, Fungal Diversity. 82: 107-182 (2017)

Ren, Guang-Cong, Wanasinghe, Dhanushka N., Jeewon, Rajesh, Monkai, Jutamart, Mortimer, Peter E., Hyde, Kevin D., Xu, Jian-Chu & Gui, Heng, 2022, Taxonomy and phylogeny of the novel rhytidhysteron-like collections in the Greater Mekong Subregion, MycoKeys 86, pp. 65-85 : 65

Rhytidhysteron tectonae Doilom & K.D. Hyde, Fungal Diversity. 82: 107-182 (2017)

Figure 3

Description.

Saprobic on decaying wood. Sexual morph Hysterothecia 550-950 µm long, 450-600 µm high, 400-500 diam. (x̄ = 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 (x̄ = 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 (x̄ = 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 (x̄ = 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.

Habitat and distribution.

Known to inhabit dead branches of Tectona grandis , Betula sp. ( Betulaceae ) and Fabaceae sp (Thailand) (Doilom et al. 2017; this study).

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. (2017) 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 tef 1-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 (Figure 1 ). 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.

Figures

Figure 1. RAxML tree based on a combined dataset of partial SSU, LSU, ITS, and tef 1 - α sequence analyses. Bootstrap support values for ML and MP equal to or higher than 75 % and Bayesian PP equal to or greater than 0.95 are shown at the nodes. Hyphens (--) represent support values less than 75 % / 0.95 BYPP. The ex-type strains are in bold and the new isolate in this study is in blue. The tree is rooted with Gloniopsis calami (MFLUCC 15 - 0739) and G. praelonga (CBS 112415).

Figure 3. Rhytidhysteron tectonae (HKAS 115533) a, b Hysterothecium on wood c vertical section through hysterothecia d exciple e pseudoparaphyses f-i immature and mature asci j ocular chamber. k-r immature and mature ascospores s Germinating ascospore t, u culture characters on PDA (t = above view, u = reverse view). Scale bars: 300 μm (c); 50 μm (d); 30 μm (e); 50 μm (f-i); 10 μm (j-r); 15 μm (s); 25 mm (t, u).