Rhamphoriaceae Réblová, Mycologia: 110(4):750–770 (2018)

Index Fungorum number: IF823918; 17 species.

Saprobes on wood. Sexual morph: Ascomata perithecial, immersed or particularly erumpent becoming superficial, papillate or with a central cylindrical or rostrate neck. Ostiole periphysate. Peridium leathery to fragile, comprising two layers. Paraphyses consisting of septate, cylindrical paraphyses. Asci 8-spored, unitunicate, cylindrical or cylindrical-clavate, persistent, with a J-, apical ring. Ascospores overlapping uniseriate, hyaline or brown, ellipsoidal, obovoid, clavate, fusiform to fusiform-clavate, dictyoseptate or transversely septate, lacking mucilaginous sheaths or appendages, in some species ascospores may produce ascoconidia while in the asci (e.g. Rhamphoria pyriformis). Asexual morph: Hyphomycetous. Conidiophores macronematous or semi-macronematous, mononematous or loosely fasciculate. Conidiogenous cells producing conidia holoblastically, conidial secession rhexolytic on sympodially extending polyblastic conidiogenous cells, or schizolytic on monoblastic conidiogenous cells. Conidia hyaline (Rhamphoria, Rhamphoriopsis, Rhodoveronaea and Xylolentia) or brown (Linkosia multiseptum), aseptate or septate (adapted from Réblová & Štěpánek 2018).

Type genusRhamphoria Niessl

NotesRhamphoriaceae was introduced by Réblová & Štěpánek (2018) with Rhamphoria as the type genus and included the genera Rhamphoriopsis, Rhodoveronaea, Xylolentia and a dematiaceous hyphomycete Linkosia multiseptum. They formed a monophyletic clade with high statistical support based on a combined dataset of SSU, LSU and rpb2 sequences. Munk (1957) placed Rhamphoria in the subfamily Rhamphorioidae of the Diaporthaceae based on morphology. However, the position of Rhamphoria in the Sordariomycetes was uncertain (Lumbsch & Huhndorf 2010). A strongly supported monophyletic clade based on LSU sequence data of Rhamphoria delicatula and Rhodoveronaea varioseptata was recovered and selected as members of the Sordariomycetidae (Réblová 2009). Despite Rhamphoria and Rhodoveronaea differing in sexual characters, their asexual morphs are similar dematiaceous hyphomycetes with same mode of conidiogenesis. These genera (except for Linkosia) share a few features such as perithecial ascomata, absence of stromatic tissues or clypeus, similar anatomy of the two-layered peridium, unitunicate, pedicellate asci with a J-, apical ring, cylindrical paraphyses and dictyoseptate or transversely septate ascospores (Réblová & Štěpánek 2018). Linkosia multiseptum, on the other hand, lacks conidiophores, has distoseptate, thick-walled conidia and ampulliform, monoblastic conidiogenous cells. Based on the morphology, it is unexpected to place L. multiseptum in Rhamphoriaceae. Shenoy et al. (2006) suggested that Linkosia (Hernández-Gutiérrez & Sutton 1997) is polyphyletic, based on LSU sequence data. The most similar relatives of Rhamphoriaceae are members of the Sporidesmiaceae (Su et al. 2016b).

Ecological and economic significance of Rhamphoriaceae: Members of Rhomphoriaceae are saprobes of decaying wood, reported predominantly from temperate regions of Europe. Members of Rhamphoria are uncommon except for R. pyriformis, which occurs on various hard wood trees (Munk 1948, 1957, Sivanesan 1976, Müller & Samuels 1982a, Réblová & Štěpánek 2018). Other Rhamphoria species have been collected only a few times and mostly only once (Réblová & Štěpánek 2018).

Figure – Phylogram generated from maximum likelihood analysis based on combined LSU, SSU, ITS and rpb2 sequence data of Diaporthomycetidae. One hundred and ninety-three strains are included in the combined analyses which comprised 3545 characters (859 characters for LSU, 972 characters for SSU, 659 characters for ITS) after alignment. Single gene analyses were carried out and the topology of each tree had clade stability. Tree topology of the maximum likelihood analysis is similar to the Bayesian analysis. The best RaxML tree with a final likelihood value of – 68207.368884 is presented. Estimated base frequencies were as follows: A = 0.248206, C = 0.241993, G = 0.285500, T = 0.224301; substitution rates AC = 1.369088, AG = 2.887040, AT = 1.413053, CG = 1.152137, CT = 6.303994, GT = 1.000000; gamma distribution shape parameter a = 0.315782. Bootstrap support values for ML greater than 75% and Bayesian posterior probabilities greater than 0.95 are given near the nodes. The tree is rooted with Diatrype disciformis (AFTOL-ID 927). Ex-type strains are in bold. The newly generated sequences are indicated in blue.