Insights into the molecular phylogeny and morphology of three novel Dothiora species, along with a worldwide checklist of Dothiora.

Most species of Dothiora are known from the dead parts of various host plants as saprobic fungi in terrestrial habitats occurring in tropical and temperate regions. In the present study, samples of Dothiora were collected from dead twigs and branches of Capparis spinosa, Rhaponticum repens, and an unknown angiosperm plant from the Tashkent and Jizzakh regions of Uzbekistan. Multi-gene phylogenetic analyses based on a combined ITS, LSU, SSU, TEF1, and TUB2 sequence data revealed their taxonomic positions within the Dothideaceae. Three new species of Dothiora, namely, Dothiora capparis, Dothiora rhapontici, and Dothiora uzbekistanica were proposed by molecular and morphological data. Likewise, the phylogenetic relationship and morphology of Dothiora are discussed. In addition, we provide a list of accepted Dothiora species, including host information, distribution, morphology descriptions, and availability of sequence data, to enhance the current knowledge of the diversity within Dothiora.

They seldom occur alone.

Species of Coleophoma have been reported as plant pathogenic, saprobic or endophytic on a wide host range. The genus is characterised by having pycnidial conidiomata, phialidic conidiogenous cells intermingled among paraphyses, and cylindrical conidia. Coleophoma has had a confusing taxonomic history with numerous synonyms, and its phylogeny has remained unresolved. The aim of the present study was to use a polyphasic approach incorporating morphology, ecology, and molecular data of the partial large subunit of nrDNA (LSU), the internal transcribed spacer region with intervening 5.8S nrDNA (ITS), partial ß-tubulin (tub2), and translation elongation factor 1-alpha (tef1) gene sequences to resolve its taxonomy and phylogeny. Based on these results the genus was found to be polyphyletic, with taxa tentatively identified as Coleophoma clustering in Dothideomycetes and Leotiomycetes. Species corresponding to the concept of Coleophoma s.str. (Dermateaceae, Helotiales, Leotiomycetes) were found to form a distinct clade, with five new species. Furthermore, Coleophoma was found to be linked to the newly established sexual genus, Parafabraea, which is reduced to synonymy. Isolates occurring on Ilex aquifolium in the Netherlands also clustered in Dermateaceae, representing a novel genus, Davidhawksworthia. In the Dothideomycetes, several taxa clustered in Dothiora (Dothideaceae, Dothideales), which is shown to have Dothichiza and Hormonema-like asexual morphs, with four new species. Furthermore, Pseudocamaropycnis is introduced as a new genus (Mytilinidiaceae, Mytilinidiales), along with Briansuttonomyces (Didymellaceae, Pleosporales) and Dimorphosporicola (Pleosporaceae, Pleosporales).

Phyllosticta ophiopogonis sp. nov. from Ophiopogon japonicus (Liliaceae).

A leaf spotting disease of an ornamental variety of Ophiopogon japonicus was discovered at several locations in northern Thailand. In all cases a species of Phyllosticta was associated with the lesions. Phyllosticta ophiopogonis sp. nov. is distinguished from Phyllosticta species from Liliaceae in conidia size, mucilaginous sheath and appendage thus the species is introduced as new in this paper. The new species which causes unsightly lesions on this ornamental plant is described, illustrated and compared with other similar Phyllosticta species.

The influence of ortho- and para-diphenoloxidase substrates on pigment formation in black yeast-like fungi.

Dothideaceous black yeast-like fungi (BYF) are known to synthesise DHN-melanin that is inhibited by the systemic fungicide tricyclazole. The final step of the DHN melanin pathway is the conjoining of 1,8-DHN molecules to form the melanin polymer. There are several candidate enzymes for this step, including phenoloxidases such as tyrosinase and laccases, peroxidases, and perhaps also catalases. We analysed the type polyphenoloxidases that are involved in biosynthesis of BYF melanins. For that purpose we used substrates of o-diphenoloxidases (EC 1.10.3.1.): 4-hydroxyphenyl-pyruvic acid, L-beta-phenyllactic acid, tyrosine, pyrocatechol, 3,4-dihydroxyphenylalanine and homogentisic acid, as well as substrates of p-diphenoloxidases (EC 1.10.3.2.): syringaldazine, resorcinol, p-phenylenediamine, phloroglucinol, guaiacol and pyrogallic acid. Fourteen strains of black yeasts originating from different natural biotopes were investigated. The tested strains could be divided into four groups based on their ability to produce dark pigments when cultivated on aromatic substrates of o- and on p-diphenoloxidases. It was established that syringaldazine, pyrogallic acid and 4-hydrophenyl-pyruvic acid, beta-phenyllactic acid optimally promote melanin biosynthesis. Average intensity of pigmentation of all strains studied was minimal when guaiacol was used as a substrate. The present investigation indicates that the melanisation process may involve more enzymes and more substrates than those commonly recognised. Black yeasts are likely to contain a multipotent polyphenoloxidase.