Pseudochaetosphaeronema lincangensis
Pseudochaetosphaeronema lincangense R.F. Xu & Tibpromma [as 'lincangensis'], in Xu, Karunarathna, Phukhamsakda, Dai, Elgorban, Suwannarach, Kumla, Wang & Tibpromma, Index Fungorum 103: 82 (2024)
Index Fungorum number: IF 663537
Saprobic on a dead branch of Hevea brasiliensis. Sexual morph: Ascomata 140–245 μm high, 255–290 μm diam., (
= 190 × 267 μm, n = 5), immersed, visible as dark-brown dots on the host surface, solitary, uni-loculate, ampulliform, without ostiole. Peridium 18–50 μm wide, several layers, comprising dark-brown to pale-brown cells of textura angularis. Hamathecium comprises 2–3 μm wide, numerous, hyaline, unbranched, pseudoparaphyses. Asci 90–145 × 15–30 μm ( = 112 × 22 μm, n = 15), 8-spored, bitunicate, cylindrical to clavate, apically rounded, short pedicelate, with a small ocular chamber, thick-walled. Ascospores 25–40 × 8–15 μm (= 30 × 11 μm, n = 35), overlapping, 2-seriate, fusiform, 1-septum in the middle of cell, widest at the centre and tapering towards narrow ends, constricted at the septum, hyaline, guttulate, with ellipsoid mucilaginous sheath, thick and smooth-walled. Asexual morph: Undetermined.
Culture characteristics: culture on PDA, colonies slow growing on 28 °C, low convex, entire, smooth, edge is off-white from above, dark brown, edge is orange on reverse side.
Material examined: China, Yunnan Province, Lincang on a dead branch of Hevea brasiliensis, 28 July 2022, Rui-Fang Xu, LCR07 (ZHKU 23–0105, holotype); ex-type ZHKUCC 23–0800, ZHKUCC 23–0801.
GenBank number: ZHKUCC 23–0800 = ITS: OR853095, LSU: OR922336, SSU: OR922342, tef1-α: OR966290; ZHKUCC 23–0801 = ITS: OR853096, LSU: OR922337, SSU: OR922343, tef1-α: OR966291.
Notes: In the phylogenetic analyses, Pseudochaetosphaeronema lincangensis clusters distinctly, sister to P. kunmingense, P. magnoliae and P. siamensis with 90% MP, 1.00 PP support. The base pair differences in ITS, LSU, SSU and tef1-α sequences of our new species are compared with P. kunmingense, P. magnoliae and P. siamensis. However, we could not compare the morphological characteristics of the species above, as they were described, based on asexual morphs. Therefore, based on morphology and phylogeny, we introduce Pseudochaetosphaeronema lincangensis as a new species.
Figure 1. Phylogram generated from Maximum Likelihood analysis based on combined LSU, ITS, SSU, tef1-α and rpb2 sequence data of 119 taxa, which comprised 4399 base pairs (LSU = 908 bp, ITS = 512 bp, SSU = 1000 bp, tef1-α = 925 bp, rpb2 = 1054 bp). The best scoring RAxML tree with a final likelihood value of -38918.764563 is presented. The matrix had 2023 distinct alignment patterns, with 39.00% of undetermined characters or gaps. Estimated base frequencies were as follows: A = 0.245191, C = 0.247520, G = 0.268228, T = 0.239061; substitution rates: AC = 1.533778, AG = 3.877174, AT = 1.672983, CG = 1.254032, CT = 8.838860, GT = 1.000000; gamma distribution shape parameter α = 0.208600. Bootstrap support values for ML equal to or greater than 60% and Bayesian Inference analysis values equal to or greater than 0.90 PP are labelled at each node. The tree is rooted with Seriascoma didymospora (MFLUCC 11–0179) and S. didymospora (MFLUCC 11–0194).
Figure 2. Pseudochaetosphaeronema lincangensis (ZHKU 23–0105, holotype) a, b appearance of ascomata on host substrate c vertical section of an ascoma d section of peridium e pseudoparaphyses f–i asci j a germinated ascospore l–q ascospores k ascospore stained with Indian ink r, s colonies on PDA (r-front and s-reverse views). Scale bars: 100 µm (c); 50 µm (d); 30 µm (e–j); 200 µm (g); 10 µm (k, l–q).
- Xu R-F, karunaratha SC, Phukhamsakda C, Dai D-Q, et al. (2024) Four new species of Dothideomycetes (Ascomycota) from Pará Rubber (Hevea brasiliensis) in Yunnan Province, China. MycoKeys 103, 71–95.
Recent Genus
EpicoccumAmphisphaeria
Paraeutypella
Recent Species
Epicoccum diplopterygiiTorula chromolaenae
Periconia delonicis