Paraconiothyrium archidendri Verkley, Göker & Stielow, in Verkley et al. Persoonia 32, 37 (2014).
Index Fungorum number: IF800761, MycoBank number: MB800761, Facesoffungi number: FoF 05243.
Saprobic on Dipterocarpus alatus woody litter. Sexual morph: Ascomata 174–232 μm high × 211–288 μm diam. (x̅ = 212 × 242 μm, n = 5), less commonly solitary or 2–4-clustered, semi-immersed, erumpent, unilocular, compressed globose, coriaceous, dark brown to black. Peridium 15.5–27 μm wide (x̅ = 20 μm, n = 35), outer layer comprises dark brown, thick-walled, tightly packed cells of textura angularis, inner layer comprises hyaline, thin-walled, loosely packed cells of textura angularis. Hamathecium comprises 1.6–3 μm wide (x̅ = 2.0 μm, n = 25), filiform to cylindrical, aseptate, branched, cellular pseudoparaphyses. Asci 60–95(–120) × 6.5–8.5 μm (x̅ = 76 × 7.8 μm, n = 20), bitunicate, fissitunicate, 8-spored, mostly clavate to cylindric-clavate, moderately curved, shallow ocular chamber at the rounded apex. Ascospores 10–14.5 × 3.5–6 μm (x̅ = 12.5 × 4.5 μm, n = 30), overlapping 1–2-seriate, light brown, oblong to fusiform, straight or sometimes curved, 1-septate at middle, constricted at septum, slightly pointed at ends, thick-walled, guttulate, without a mucilaginous sheath. Asexual morph: Undetermined.
Culture characteristics – Ascospore germinated on PDA within 24 h. Colonies reaching 35 mm diam. after 10 days on PDA at room temperature (25–28 °C), circular, umbonate, wrinkled, folded in the middle, velvety, dense, non-pigmented, with two distinct layers, narrow towards the fringe, at the upper surface white, from the reverse white at the margin, and yellowish-brown in the center.
Material examined – Thailand, Chiang Rai Province, Doi Tung National Park, on dead wood of Dipterocarpus alatus (Dipterocarpaceae), 26 March 2022, N. Afshari, 2C1T1R4a (MFLU 24-0399); living culture MFLUCC 24-0528.
GenBank numbers – ITS: PQ800231, LSU: PV072589, tub2: PX739616.
Known hosts – Pithecellobium bigeminum (Verkley et al. 2014), an unidentified one from plant litter (Goh et al. 2016), Leucaena sp. (Jayasiri et al. 2019), Magnolia sp. (Tennakoon et al. 2022a), Dipterocarpus alatus (this study).
Known distribution – Myanmar (Verkley et al. 2014), Korea (Goh et al. 2016), Thailand (Jayasiri et al. 2019, this study), China (Tennakoon et al. 2022a)
Notes – Phylogenetic analyses demonstrated that our strain (MFLUCC 24-0528) formed a clade with eight other isolates of P. archidendri, specifically grouping with P. archidendri (1-3- 10-2-1-4) (97% ML/ 0.99 PP bootstrap support). Paraconiothyrium archidendri was isolated from leaf spots of Pithecellobium bigeminum in Myanmar (Verkley et al. 2014). In previous collections of P. archidendri, the sexual morph was not reported. Most species have been found in asexual morph, and only P. fuckelii exhibited both sexual and asexual forms (Wang et al. 2021b). Based on multigene phylogeny, our new collection represents the first report of the sexual morph of P. archidendri and is reported as a new host record from Dipterocarpus alatus.
Figure 1 – Phylogram generated from maximum likelihood analysis based on the combined ITS, LSU, and tub2 sequence data of Paraconiothyrium. Tree topology of the maximum likelihood analysis is similar to the Bayesian analysis. Fifty-four strains are included in the combined analyses 4828, which comprised 2,307 characters (ITS = 504, LSU = 1,358, and tub2 = 445). The best RAxML tree with a final optimization likelihood value of -7497.531186 is presented. The matrix had 580 distinct alignment patterns, with 40.45% of undetermined characters or gaps. Estimated base frequencies were as follows: A = 0.231688, C = 0.247955, G = 0.281583, T = 0.238774; substitution rates AC = 1.488240, AG = 3.323098, AT = 1.440713, CG = 0.961639, CT = 6.911311, GT = 1.000000; gamma distribution shape parameter α = 0.136352. In the Bayesian analysis, average standard deviation of split frequencies at the end of 10,000,000 MCMC generations was calculated as 0.012683. The evolutionary models TrN+I+G, were applied for ITS, and LSU, and TPM2uf+G was applied for tub2 sequence data. Bootstrap support values for ML greater than or equal to 70% and Bayesian posterior probabilities greater than or equal to 0.90 are given above the nodes. The strain codes are noted after the species names. The tree is rooted with Tremateia guiyangensis (GZAAS01) and T. arundicola (MFLU 16-1275). Ex-type strains are in bold. The isolate generated in this study is indicated in bold and blue.
Figure 2 – Sexual morph of Paraconiothyrium archidendri (MFLU 24-0399, a new host record and first report of the sexual morph). a, b Appearance of ascomata on Dipterocarpus alatus woody litter. c, d Vertical section of ascomata. e Section of peridium. f Paraphyses. g–m Asci. n–s Ascospores. t Colony on PDA from above and reverse. Scale bars: a = 1 mm, b = 200 μm, c, d = 50 μm, e–m = 20 μm, n–s = 10 μm.