Plenodomus artemisiae
Plenodomus artemisiae A. Karunarathna, Phookamsak & K.D. Hyde, Fungal Diversity 95: 1–273 (2019)
Index Fungorum number: IF 556118; Facesoffungi Number: FoF 05696
Saprobic on dead branch of Quercus serrate. Sexual morph: Ascomata 160–200 μm high, 200–320 μm diam., solitary to aggregate, immersed, uniloculate, subglobose black, shiny on the host surface, with truncated base, glabrous, ostiolate central. Peridium 10–50 μm wide, thick-walled of unequal thickness, thickened at the sides, thin at the base and apex, composed of several cell layers of light brown cells, arranged in a textura angularis to textura globulosa. Hamathecium 2.5–4.7 μm wide, composed of hyaline, filamentous, septate, pseudoparaphyses. Asci 80–100 × 11–13.8 μm (x̅ = 92 × 12.5 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical, short pedicellate, apically rounded with a distinct ocular chamber. Ascospores 32–37 × 5–7 μm (x̅ = 35 × 5.8 μm, n = 20), overlapping biseriate, pale brown, fusiform, slightly curve, 5-septate, slightly constricted at the septa, enlarge at the third cell from above, gettules, lacking a mucilaginous sheath and appendages. 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 55 mm diameter after two weeks at 20–25 ℃, mycelia superficial, circular, dense, white-grey, smooth, downy, fimbriate; reverse atrovirens.
Material examined: China, Yunnan Province, Lijiang, on dead woody twigs of Quercus serrate (Fagaceae), 30 August 2020, G.C. Ren, DQ17 (HKAS 122717), living culture KUMCC 21-0534.
Known distribution: Artemisia sp. (Anthemideae) in China (Phookamsak et al. 2019), dead stems of Artemisia argyi (Anthemideae) in China (Doilom et al. 2021) and Quercus serrate (Fagaceae) in China.
GenBank numbers: SSU: OQ168211, LSU: OQ170857, ITS: OQ158935.
Notes: In phylogenetic analyses, our new collection (KUMCC 21-0534) clustered with other Plenodomus artemisiae strains (KUMCC 18-0151, KUMCC 20-0200A and KUMCC 20-0200B) with 98% ML bootstrap support and 1.00 BYPP value. The new collection shares similar morphology with the type of P. artemisiae in having immersed, uniloculate, subglobose black ascomata with truncated base, thick-walled of unequal thickness, thickened at the sides, thin at the base and apex peridium, bitunicate, fissitunicate, cylindrical asci with a distinct ocular chamber, overlapping biseriate, pale brown, fusiform, slightly curve, 5-septate ascospores (KUMCC 18-0151) (Phookamsak et al. 2019). Our collection has 99.60%, 99.64%, and 99.9% similarities with the ex-type strain (KUMCC 18-0151) of P. artemisiae in ITS, LSU and SSU sequence data, respectively, which indicate them to be conspecific. Therefore, we identified our collection as P. artemisiae based on morphological and molecular evidence. Our new collection was collected from the same region as the previous records (Phookamsak et al. 2019, Doilom et al. 2021) but from a different host (Quercus serrata).
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.
Figure 2. Plenodomus artemisiae (HKAS 122717). a Material examined. b Appearance of ascomata on the host substrate. c Section of an ascoma. d Peridium. e Pseudoparaphyses. f–h Asci. i–o Ascospores. p, q Culture characters on PDA (p = from above, q = from below). Scale bar: c = 100 μm, d = 50 μm, e = 10 μm, f–h = 50 μm, i–o = 20 μm, p, q = 30 mm.
References
- Ren GC, Jayasiri SC, Tibpromma S, De Farias ARG, et al. (2024) Saprobic ascomycetes associated with woody litter from the Greater Mekong Subregion (Southwestern China and Northern Thailand). Mycosphere 15(1), 954–1082, Doi 10.5943/mycosphere/15/1/8
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