Aliquandostipite khaoyaiensis Inderbitzin, Am. J. Bot. 88: 54 (2001)

Index Fungorum number: IF 483979; MycoBank number: MB 483979; Facesoffungi number: FoF 09158; Fig. 1

Saprobic on submerged wood. Sexual morph Ascomata 340–415 μm high, 250–290 μm diam., hyaline to pale brown, becoming dark brown with age, scattered, superficial, sometimes seated in a pseudostroma, globose or subglobose, sessile, membranous, papillate, ostiolate. Ostioles 100–135 μm apically lined by elongated cells. Peridium 30–40 μm thick, membranous, composed of thin-walled, pale brown, compressed cells of textura angularis. Pseudoparaphyses 2–5 μm diam., numerous, sparsely branched, hyaline, septate. Asci 155–200×35–65 μm (x̅=175×50 μm, n=20), 8-spored, bitunicate, fissitunicate, clavate, thickened at apex, sessile or short pedicellate, with a well-developed ocular chamber. Ascospores 55–70×15–25 μm (x̅=65×19 μm, n = 30), variably arranged in asci, oval, hyaline to pale brown, 1-septate, deeply constricted at the septum, asymmetric, upper cell shorter and wider than lower cell, guttulate, straight or curved, thin-walled, smooth, sheathed. Sheath first appressed to the ascospore wall, expanding and detaching from the polar regions when mounted in water, becoming balloon-like at the two poles, finally surrounding the entire ascospore. Asexual morph Undetermined.

Culture characteristics – Conidia germinating on malt extract agar (MEA) within 24 h. Germ tubes produced from the basal and apical cells of conidia. Colonies growing on MEA, reaching 20–25 mm in 2 weeks at 25 °C, colony circular, entire edge, dry, surface rough, with dense mycelium, pale yellow from above, dark brown from below

Material examined – THAILAND, Phitsanulok Province, Wang Thong, Kaeng Sopha stream, on submerged wood, 25 July 2019, S. Boonmee, ISAN100 (MFLU 21-0125, new record), living culture, MFLUCC 21-0106.

GenBank numbers – ITS=MT864350, LSU=MT860428, SSU = MT860445, TEF1-α = MT873577, RPB2=MT873578.

Notes – Aliquandostipite khaoyaiensis has been recorded from Costa Rica (Raja et al. 2005), Thailand (Campbell et al. 2007) and U.S.A. (Raja et al. 2009). Our isolate MFLUCC 21-0106 resembles the generic description of the species except it lacks stalked ascomata. Furthermore, A. khaoyaiensis (MFLUCC 21-0106) has shorter ascospores compared to A. khaoyaiensis UBC F13875, the holotype isolated from Khao Yai National Park, Thailand (55–70×15–25 μm vs. 39–52×16–23 μm). In the phylogenetic tree, our new isolate clustered with other strains of A. khaoyaiensis and A. siamensis with 99% MPBS, 0.99 BYPP support (Fig. 2), which appears to be conspecific. Aliquandostipite siamensis is distinct from A. khaoyaiensis in having dimorphic, hyaline or brown ascospores without a sheath while the latter produces monomorphic, pale brown ascospores with well-developed sheaths (Inderbitzin et al. 2001; Pang et al. 2002; Campbell et al. 2007). We therefore report our collection as a fourth record of A. khaoyaiensis from submerged wood in Thailand (Fig. 1).

Figure 1 –  Aliquandostipite khaoyaiensis (MFLU 21-0125, new record). a, b Ascomata superficial on host surface. c Peridium cells. d Pseudoparaphyses. e, f Asci. g Ascospores. Scale bars: a, b, e, f=200 μm, c, g=100 μm, d=20 μm

Figure 2 – Phylogram generated from maximum likelihood analysis based on combined LSU, SSU, ITS, TEF1-α and RPB2 sequence data representing the species of Aliquandostipite. Related sequences are taken from Suetrong et al. (2011). Jahnula sangamonensis (F81-1) and J. dianchia (KUMCC 17-0039) in Aliquandostipitaceae (Jahnulales) were used as the outgroup taxa. Fourteen taxa are included in the combined analyses which comprised 4306 characters (1006 characters for LSU, 1005 characters for SSU, 587 characters for ITS, 726 characters for TEF1-α, 982 characters for RPB2) after alignment. The best scoring RAxML tree with a final likelihood value of − 8403.913612 is presented. The matrix had 301 distinct alignment patterns, with 51.74% of undetermined characters or gaps. The MP analysis resulted a single most parsimonious tree (TL=442, CI=0.986, RI=0.977, RC=0.964, HI=0.014). Bootstrap support values for ML and MP equal to or greater than 75% and BYPP equal to or greater than 0.95 are given above the nodes. The newly generated sequence is in blue