Parapolyplosphaeria Rajeshk., C.G. Lin, Dong Wei & K.D. Hyde., gen. nov.

Index Fungorum number: IF 901424;  Mycobank number: MB 901424; Facesoffungi number: FoF 16040

Etymology – epithet Parapolyplosphaeria is derived from Polyplosphaeria due to the morphological similarities with the genus.

Type species – Parapolyplosphaeria thailandica (C.G. Lin, Yong Wang bis & K.D. Hyde) Rajeshk., C.G. Lin, Dong Wei & K.D. Hyde.

Saprobic on bamboo culms. Mycelium superficial. Sexual morph Not observed. Asexual morph Conidiophores absent. Conidiogenous cells monoblastic. Conidia solitary, dry, acrogenous, muriform, globose, obovoid, pyriform, ellipsoidal, occasionally two conidial body fused together at the basal cell, brown, 2–5 appendages, grey to brown, straight, septate, rounded at the apex, basal cell usually cylindrical, obconical, dark brown, smooth-walled.

Note – Polyplosphaeria was introduced by Tanaka et al. (2009) with the type species Polyplosphaeria fusca Kaz. Tanaka & K. Hiray defined based on its sexual and asexual morphs. The anamorphic state of Polyplosphaeria produces globose to subglobose conidia composed of numerous internal hyphae, thin peel-like outer wall, and three to eight setose appendages (Tanaka et al. 2009). Our multi-locus sequencing data analyses (Fig. 32) of Tetraplosphaeriaceae Kaz. Tanaka & K. Hiray. delineated Polyplosphaeria thailandica C.G. Lin, Yong Wang & K.D. Hyde, as a paraphyletic lineage that form a distant lineage from Polyplosphaeria
sensu stricto Clade representing its type Polyplosphaeria fusca. After Ernakulamia and Shrungabeeja sequences were introduced into the phylogenetic analysis of Tetraplosphaeriaceae, Polyplosphaeria thailandica was consistently form a paraphyletic lineage (Hyde et al. 2020a, b, c; Phookamsak et al. 2022; Liao et al. 2022). In our analysis (IQ tree, RAxML and MrBayes), P. thailandica formed a separate clade sister to the members of Shrungabeeja (Fig. 1). The morphological comparison of P. fusca with P. thailandica also supported differences in conidial characteristics such as size, shape and appendage number. P. thailandica has some unique features like grey to brown conidia and occasionally two conidia associated together at the basal cell, which are not reported in other members of Polyplosphaeria (Tanaka et al. 2009; Tibpromma et al. 2018). Likewise, only 2–5 appendages were reported in P. thailandica while more than 5 both long and short appendages were key characters of Polyplosphaeria. Considering these consolidated evidences, we propose a new genus Parapolyplosphaeria, for Polyplosphaeria thailandica as Parapolyplosphaeria thailandica. The genera Aquatisphaeria, Ernakulamia, Parapolyplosphaeria and Shrungabeeja were delineated consistently as sister clades in all the analyses (IQ-TREE (ML-BS), RAxML (R-BS) and Bayesian analysis (PP).

Figure 1 – Phylogenetic tree obtained from an IQ-TREE analysis of species from Tetraplosphaeriaceae based on combined LSU, ITS, SSU, and tef1-α sequences. Related sequences are taken from Phookamsak et al. (2022) and additions according to the BLAST searches in NCBI. 45 sequences are included in the analysis which comprises 3385 characters (1462 characters for LSU, 588 characters for ITS, 1366 characters for SSU, 918 characters for tef1-α) after alignment. The evolutionary model SYM+I+G4 was used for IQ tree analysis. RAxML analysis and Bayesian inference were implemented with the GTR+I+G model. Muritestudina chiangrainensis (MFLUCC 17-2551) was used as the outgroup taxa. The best-scoring IQ tree with a final likelihood value of − 11,834.995 is presented. The matrix had 728 distinct alignment patterns, with 28.55% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.250, C=0.250, G=0.250, T=0.250; substitution rates: AC=3.75859, AG=4.80170, AT=2.27679, CG=1.64189, CT=10.27537, GT=1.00000; gamma distribution shape parameter α=0.569. Branch support values from 1000 non-parametric bootstraps for IQ-TREE (ML-BS) and RAxML (R-BS) and posterior probability values from the Bayesian analysis (BYPP) are shown at the nodes. Bootstrap support values for ML equal to or greater than 50% are given above the nodes. Bayesian posterior probabilities (BYPP) equal to or greater than 0.90 are given above the nodes. Extype strains are in bold and newly generated sequences as well as new combinations are in blue bold

Species