Lentithecium yunnanense
Lentithecium yunnanense W.H. Lu, Karun. & Tibpromma [as ‘yunnanensis’], in Lu, Dai, Lu, Liu, Wei, Karunarathna & Tibpromma, Phytotaxa 554 (2): 108 (2022)
Index Fungorum number: IF 658975; Facesoffungi Number: FoF10778
Saprobic on dead woody twigs of Castanopsis orthacantha. Sexual morph: Ascomata 140 –210 μm diam., 150 –200 μm high (x̅ = 180 × 160 μm, n = 5), scattered to gregarious, semi-immersed to immersed beneath the host epidermis, sometimes sparse erumpent, subglobose to globose in section, with a short papillate, ostiolar neck. Ostioles 58–93 μm long, 83–120 μm diam., (x̅ = 76 × 98 μm, n = 5), central, black. Peridium 17–25 μm wide, multi-layered, consists of dark–brown, thick-walled cells of textura angularis in the outermost layers of unequal thickness. Hamathecium comprising 1.5–2 μm wide, hyaline, slenderly cylindrical, septate, unbranched, rarely anastomosing, tubular psedoparaphyses. Asci 73–90 × 12.7–16 μm (x̅ = 80 × 14.4 μm, n = 20), 8–spored, fissitunicate, bitunicate, oblong to cylindrical, broadly rounded apex, with visible apical chambers, short, club-shaped pedicel. Ascospores 24–29 × 6–7.7 μm (x̅ = 26.6 × 7 μm, n = 20), overlapping biseriate, hyaline, clavate to broadly fusiform, slightly curved, 1–3-septate, slightly constricted at the middle septum, widest at the centre, tapering towards the broadly rounded ends, smooth-walled, with large guttules, surrounded by a hyaline, mucilaginous sheath. Asexual morph: Undetermined.
Culture characteristics: Ascospores germinating on PDA within 24 h at room temperature (25 °C). Germ tubes produced from the basal and apical cell of ascospore. Colonies on PDA, reaching 45 mm diameter after two weeks at 20–25 ℃, mycelia superficial, circular, atrovirens, smooth, downy, fimbriate; reverse atrovirens, crack.
Material examined: China, Yunnan Province, Baoshan, on dead woody twigs of Castanopsis orthacantha (Fagaceae), 23 July 2020, G.C. Ren, BS47 (HKAS 122714), living culture KUMCC 21-0525
.
Known distribution: On dead culms of Artemisia sp. (Proteaceae) and dead woody twigs of Castanopsis orthacantha (Fagaceae) in China (Lu et al. 2022a, Ren et al. 2024).
GenBank numbers: SSU: OQ168208, LSU: OQ170854, ITS: OQ158932, tef1-α: OR613430.
Notes: According to the multi-gene phylogenetic analyses of combined SSU, LSU, ITS and tef1-α sequence dataset, our new isolate (KUMCC 21-0525) nested with Lentithecium yunnanense (KUNCC 22-10776 and KUNCC 22-10777), which was isolated from Artemisia sp. (Proteaceae) in China (Lu et al. 2022a) with 100% ML bootstrap support and 1.00 BYPP value. Our new isolate fits well with the characters of the holotype of L. yunnanense in having semi-immersed to erumpent, subglobose to globose ascomata with short papillate, ostiolar neck, oblong to cylindrical, short, club-shaped, pedicellate asci and 1–3-septate, hyaline, clavate to broadly fusiform ascospores with a mucilaginous sheath (Lu et al. 2022a). Therefore, we identified our taxon as a new host record of L. yunnanense from Castanopsis orthacantha (Fagaceae) in China.
Figure 1. Phylogram generated from ML analysis based on SSU, LSU, ITS, and tef1-α sequence data, representing Lentitheciaceae. Related sequences are obtained following Calabon et al. (2021) and Lu et al. (2022a). One hundred and one strains are included in the combined analyses, which comprise 3231 characters for SSU, LSU, ITS, and tef1-α alignment. Corynespora cassiicola (CBS 100822) and C. smithii (CABI5649b) were used as the outgroup taxa. The best-scoring RAxML tree with a final likelihood value of -21283.940390 is presented. The matrix had 1239 distinct alignment patterns, with 25.09% of undetermined characters or gaps. Estimated base frequencies were as follows; A = 0.240228, C = 0.247293, G = 0.273128, T = 0.239351; substitution rates AC = 1.200390, AG = 2.125722, AT = 1.347877, CG = 1.314457, CT = 8.272345, GT = 1.0000. The tree topology of the ML analysis is similar to the Bayesian analysis. Bootstrap values for ML equal to or greater than 70% and BYPP values greater than 0.95 (the rounding of values to 2 decimal proportions) are labelled on the nodes. Strains of the newly described species are in blue, while type strains are in bold.