Pleurotheciaceae Réblová & Seifert, Persoonia 37: 63 (2015)
MycoBank number: MB 813229; Index Fungorum number: IF 813229; Facesoffungi number: FoF 05316; 85 species.
Saprobic on plant tissues of a variety of hosts. Sexual morph: Ascomata perithecial, immersed, semi-immersed or superficial, papillate or with a central rarely eccentric neck. Ostiole periphysate. Peridium leathery to fragile, carbonaceous, comprising two layers, outer layer comprising brown to dark brown cells, inner layer comprising hyaline to pale brown cells. Paraphyses abundant, sparsely branched, partially disintegrating, cylindrical. Asci 8-spored, unitunicate, cylindrical or cylindrical-clavate, short or long pedicellate, with a pronounced J-, apical ring. Ascospores overlapping or 1–3-seriate, hyaline or versicolorous with polar cells hyaline and middle cells brown, ellipsoidal to fusiform, transversely multi-septate, lacking a mucilaginous sheath or appendages. Asexual morph: Conidiomata present or absent, when present indeterminate synnemata or loose fascicles. Conidiophores macronematous or semi-macronematous, sometimes elongating percurrently. Conidiogenous cells holoblastic, conidial secession rhexolytic on short denticles or rachis on sympodially extending polyblastic conidiogenous cells, or schizolytic on monoblastic or solitary thallic conidiogenous cells. Conidia hyaline, sometimes with protracted maturation of the middle cells, which turn brown, or brown or versicolorous, septate or aseptate. (adapted from Réblová et al. 2016c).
Type genus – Pleurothecium Höhn.
Notes – Pleurotheciaceae was introduced by Réblová et al. (2016c) in Pleurotheciales. Ten genera, i.e. Adelosphaeria, Brachysporiella, Helicoon, Melanotrigonum, Phaeoisaria, Phragmocephala, Pleurotheciella, Pleurothecium, Sterigmatobotrys and Taeniolella, were included in this family (Réblová et al. 2016c). Maharachchikumbura et al. (2016b) accepted eleven genera in Pleurotheciaceae including Plagiascoma, which was placed in Fuscosporellales (Réblová et al. 2016c, Yang et al. 2016b, Wijayawardene et al. 2017a, 2018a). In addition, Monotosporella and Helicoon were considered as members of Savoryellaceae (Savoryellales) in Maharachchikumbura et al. (2016b), while they were confirmed in Pleurotheciaceae by Réblová et al. (2012, 2016c). Monotosporella was treated as a synonym of Brachysporiella by Ellis (1959). Hernández-Restrepo et al. (2017) considered the genera Brachysporiella and Monotosporella distinct with support of multi-locus phylogenetic analysis, and placed the genera in Kirschsteiniotheliales and Pleurotheciales, respectively. Wijayawardene et al. (2017a) placed Brachysporiella in Pleurotheciaceae and Monotosporella in Savoryellaceae, however, Wijayawardene et al. (2018a) transferred Brachysporiella to Kirschsteiniotheliales genera incertae sedis and retained Monotosporella in Savoryellaceae. Anapleurothecium was introduced by Hernández-Restrepo et al. (2017) and placed in Pleurotheciaceae. Plagiascoma was accepted in Pleurotheciaceae by Wijayawardene et al. (2017a, 2018a).
Taeniolella, based on T. rudis, was included in Pleurotheciaceae by Réblová et al. (2016c) as sister to Sterigmatobotrys. The fertile, penicillate sterigmatobotrys-like conidiophores developing at the apex of the Taeniolella conidium were earlier reported by Réblová & Seifert (2011) suggesting a close relationship between the two genera. Ertz et al. (2016) transferred Taeniolella rudis to Sterigmatobotrys, based on the morphology of the penicillate synasexual morph and molecular data. The type species, Taeniolella exilis, was placed in Kirschsteiniotheliaceae in Dothideomycetes, and Taeniolella was recovered as strongly polyphyletic (Ertz et al. 2016). Wijayawardene et al. (2017a) placed in Kirschsteiniotheliaceae (Kirschsteiniotheliales, Dothideomycetes), however, Ekanayaka et al. (2017) transferred this genus to Mytilinidiaceae (Mytilinidiales, Dothideomycetes) and Wijayawardene et al. (2018a) accepted this treatment. In this study, we accept the treatment of Ertz et al. (2016) and excluded Taeniolella from Pleurotheciaceae.
It was shown that Helicoon is strongly polyphyletic. It was placed in three different classes, viz. Leotiomycetes, Sordariomycetes and Dothideomycetes (Tsui & Berbee 2006). Helicoon farinosum was included in Pleurotheciaceae by Réblová et al. (2016c) and Maharachchikumbura et al. (2016b) based on the support of the multi-locus phylogenetic analyses. Wijayawardene et al. (2017a) placed this genus in Orbiliaceae (Orbiliales, Orbiliomycetes), however, Wijayawardene et al. (2018a) placed it in Savoryellaceae (Savoryellales, Sordariomycetes). Dayarathne et al. (2019a) introduced Helicoascotaiwania to accommodate Ascotaiwania hughesii (asexual morph is Helicoon farinosum) and placed this genus in Pleurotheciaceae.
Phragmocephala is polyphyletic (Su et al. 2015, Réblová et al. 2016b, Hernández-Restrepo et al. 2017). Currently, there are nine species epithets in Index Fungorum (2020), however, only three of them, P. garethjonesii, P. glanduliformis and P. stemphylioides, have molecular data available. Su et al. (2015) introduced P. garethjonesii based on DNA sequence data and morphology and placed this species in Melanommataceae in Dothideomycetes. Réblová et al. (2016c) placed P. stemphylioides in Pleurotheciaceae in Sordariomycetes based on multi-locus phylogenetic analyses. Phragmocephala glanduliformis was placed in Microthyriaceae in Dothideomycetes by Hernández- Restrepo et al. (2017).
In this study, a multi-locus phylogenetic analyses based on a combined ITS, LSU, SSU and rpb2 sequence data of Pleurotheciales is presented (Fig. 10). Bayesian inference, maximum parsimony and maximum likelihood were used for phylogenetic analyses. The analyses provided similar tree topologies, which are similar with those in Réblová et al. (2016c), Yang et al. (2016b), Hernández-Restrepo et al. (2017), Hyde et al. (2017b, 2018b) and Luo et al. (2018). The problematic genera and species and the newly introduced genus after Réblová et al. (2016c), Phragmocephala stemphylioides (DAOM 673211), “Brachysporiella setosa” (HKUCC 3713) (current name: Monotosporella setosa), Anapleurothecium botulisporum (FMR 11490), “Taeniolella rudis” (DAOM 229838) (current name: Sterigmatobotrys rudis), Helicoon farinosum (current name: Helicoascotaiwania hughesii) (ILLS 53605 and DAOM 241947), are grouped in a robust clade Pleurotheciaceae (Fig. 10).
In conclusion, genera that accepted in the family in this study are: Adelosphaeria, Anapleurothecium, Helicoascotaiwania, Melanotrigonum, Monotosporella, Phaeoisaria, Phragmocephala, Pleurotheciella, Pleurothecium and Sterigmatobotrys.