Leaf-inhabiting genera of the Gnomoniaceae, Diaporthales.

The Gnomoniaceae are characterised by ascomata that are generally immersed, solitary, without a stroma, or aggregated with a rudimentary stroma, in herbaceous plant material especially in leaves, twigs or stems, but also in bark or wood. The ascomata are black, soft-textured, thin-walled, and pseudoparenchymatous with one or more central or eccentric necks. The asci usually have a distinct apical ring. The Gnomoniaceae includes species having ascospores that are small, mostly less than 25 mum long, although some are longer, and range in septation from non-septate to one-septate, rarely multi-septate. Molecular studies of the Gnomoniaceae suggest that the traditional classification of genera based on characteristics of the ascomata such as position of the neck and ascospores such as septation have resulted in genera that are not monophyletic. In this paper the concepts of the leaf-inhabiting genera in the Gnomoniaceae are reevaluated using multiple genes, specifically nrLSU, translation elongation factor 1-alpha (tef1-alpha), and RNA polymerase II second largest subunit (rpb2) for 64 isolates. ITS sequences were generated for 322 isolates. Six genera of leaf-inhabiting Gnomoniaceae are defined based on placement of their type species within the multigene phylogeny. The new monotypic genus Ambarignomonia is established for an unusual species, A. petiolorum. A key to 59 species of leaf-inhabiting Gnomoniaceae is presented and 22 species of Gnomoniaceae are described and illustrated.

The hyphomycete Teberdinia hygrophila gen. nov., sp. nov. and related anamorphs of Pseudeurotium species.

A hyphomycetous fungus isolated from montane fen soil in the Caucasus Mountains, Russia, had obscurely sympodial conidiogenous cells that suggested a link to the heterogeneous genus Leptodontidium. Sequence analysis of the nuclear ribosomal small subunit and internal transcribed spacer region, however, disclosed that the fungus was an anamorphic member of a clade containing the cleistothecial ascomycetous genus Pseudeurotium. Teberdinia, gen. nov., is proposed for the blastic, generally sympodially proliferating anamorphs in this group, and Teberdinia hygrophila, sp. nov., is proposed for the species from upland fens. Binomials are not proposed for the remaining Teberdinia anamorphs of Pseudeurotium species. Purely anamorphic isolates in this clade are difficult to recognize using current morphological keys and might be more widely distributed and ecologically significant than is currently evident.

A systematic account of the genus Plagiostoma (Gnomoniaceae, Diaporthales) based on morphology, host-associations, and a four-gene phylogeny.

Members of the genus Plagiostoma inhabit leaves, stems, twigs, and branches of woody and herbaceous plants predominantly in the temperate Northern Hemisphere. An account of all known species of Plagiostoma including Cryptodiaporthe is presented based on analyses of morphological, cultural, and DNA sequence data. Multigene phylogenetic analyses of DNA sequences from four genes (ß-tubulin, ITS, rpb2, and tef1-α) revealed eight previously undescribed phylogenetic species and an association between a clade composed of 11 species of Plagiostoma and the host family Salicaceae. In this paper these eight new species of Plagiostoma are described, four species are redescribed, and four new combinations are proposed. A key to the 25 accepted species of Plagiostoma based on host, shape, and size of perithecia, perithecial arrangement in the host, and microscopic characteristics of the asci and ascospores is provided. Disposition of additional names in Cryptodiaporthe and Plagiostoma is also discussed.