Marcin Piątek

Naming and outline of Dothideomycetes-2014 including proposals for the protection or suppression of generic names

Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this species will be considered as synonyms. The older generic epithet takes priority over the younger name. Any widely used younger names proposed for use, must comply with Art. 57.2 and their usage should be approved by the Nomenclature Committee for Fungi (NCF). In this paper, we list all genera currently accepted by us in Dothideomycetes (belonging to 23 orders and 110 families), including pleomorphic and non-pleomorphic genera. In the case of pleomorphic genera, we follow the rulings of the current ICN and propose single generic names for future usage. The taxonomic placements of 1261 genera are listed as an outline. Protected names and suppressed names for 34 pleomorphic genera are listed separately. Notes and justifications are provided for possible proposed names after the list of genera. Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes. A phylogenetic tree based on four gene analyses supported 23 orders and 75 families, while 35 families still lack molecular data.

Anther smut fungi on monocots

Teliospores, hyphal septa, cellular interactions, and nucleotide sequences from the ITS and LSU region of the rRNA gene of specimens of Ustilago vaillantii s. lat. on Muscari and Scilla species were examined and compared with findings in other Ustilaginomycotina. The data show that U. vaillantii s. lat. specimens belong to the Urocystales and represent the sister group of the Urocystaceae, standing well apart from Vankya heufleri and V. ornithogali. Within the Urocystales, U. vaillantii s. lat. is unique in sporulating in the anthers of the host plants. Accordingly, the new genus Antherospora is proposed for the anther smuts on Hyacinthaceae. In addition, our data show that there is a stringent phylogenetic correlation between the specimens of Antherospora and their respective hosts. Thus, the specimens on Scilla spp. as well as those on Muscari spp. form highly supported monophyla. Furthermore, on Scilla a phylogenetic dichotomy exists between the specimens infecting Scilla bifolia and those infecting S. vindobonensis, with the specimens of the two host species showing a difference of 17bp in the ITS nucleotide sequences. Therefore, A. vindobonensis is described as a new species, and A. scillae and A. vaillantii are proposed as new combinations. Consequently, because of their sporulation in anthers and their parasitism on species of other genera of the Hyacinthaceae, Ustilago albucae, U. peglerae, U. tourneuxii, and U. urgineae are also ascribed to Antherospora as new combinations. Descriptions are given for all species.

Microbotryum heliospermae, a new anther smut fungus parasitic on Heliosperma pusillum in the mountains of the European Alpine System.

The members of the smut genus Microbotryum are pathogens of a wide range of host plant species from nine dicotyledonous families. Within the genus, the species sporulating in anthers of Caryophyllaceae form a monophyletic group that in recent years attracted much interest in various biological studies. The phylogenetic framework developed for species delimitation within Microbotryum revealed that high level host-specificity is a major feature of most caryophyllaceous anther smuts. However, the great number of anther smut specimens on diverse host plant species reported worldwide has still not been included in phylogenetic analyses due to the inaccessibility of recently collected specimens, and thus many species remain still undiscovered. In this study, anther smut specimens on Heliosperma pusillum originating from all main mountain ranges of the European Alpine System were examined using partial rDNA sequence and/or morphological analyses. The investigation revealed that all specimens are morphologically uniform and phylogenetically represent a monophyletic lineage, sister to Microbotryum lagerheimii complex on Atocion rupestre/Silene lacera/Silene vulgaris/Viscaria vulgaris. This lineage cannot be attributed to any of the previously described species, and therefore the smut in anthers of H. pusillum is described and illustrated here as a new species, Microbotryum heliospermae. The species is known from subalpine zone of the Alps, the Carpathians, the Dinaric Alps, and the Pyrenees, inhabiting host plants growing in open spring communities or semihumid mountain meadows.

Cryptic diversity in the Antherospora vaillantii complex on Muscari species

The anther smut fungi in the ustilaginomycetous genus Antherospora (Floromycetaceae, Urocystidales) that infect monocots, are currently placed in nine species. Against the background of the generally observed high host specificity in smut fungi, the broad host range reported for some of the species suggests much higher diversity. Antherospora vaillantii s. lato includes anther smuts on different Muscari species. In this study, specimens of anther smuts on Muscari armeniacum, M. botryoides, M. comosum, and M. tenuiflorum were analysed by rDNA sequences and morphology to determine whether they represented one polyphagous or several host specific species. The molecular phylogeny revealed three distinct lineages that were correlated with host plants, yet had only slight morphological differences. These lineages are assigned to three cryptic species: Antherospora hortensis sp. nov. on Muscari armeniacum, A. muscari-botryoidis comb. nov. (syn. Ustilago muscari-botryoidis) on M. botryoides, and A. vaillantii s. str. on M. comosum and M. tenuiflorum. All species on Muscari form a monophyletic group within Antherospora, and the phylogenetic relations within this group coincide well with the subgeneric classification of the respective host species. This indicates a common ancestry of Muscari anther smuts and co-evolution as a driver of their diversification.

Erysiphe catalpae and Erysiphe elevata in Europe

The recent epidemic spread of the North American powdery mildew Erysiphe elevata in Europe is described and discussed. Since 2002, this plant pathogenic fungus has been collected on Catalpa bignonioides, C. erubescens and C. speciosa in the Czech Republic, Germany, Hungary, Slovakia and Switzerland. The diagnostically important anamorph of E. elevata, so far unknown, is described and illustrated in detail. Type material of Erysiphe catalpae and two specimens of E. catalpae recently collected in Poland have been examined and compared with E. elevata. The anamorph as well as the teleomorph of E. catalpae proved to be easily distinguishable from E. elevata. The supposition that E. catalpae, introduced in Armenia, was based on immature ascomata of E. elevata proved to be wrong. The origin and distribution of E. catalpae are discussed, and a key to powdery mildew fungi on Catalpa spp. in Europe is provided.

Shivasia gen. nov. for the Australasian smut Ustilago solida that historically shifted through five different genera

The generic position of the enigmatic smut fungus Ustilago solida is evaluated applying molecular phylogenetic analyses using ITS and LSU rDNA sequences as well as light and scanning electron microscopical investigations of several collections of this species. Ustilago solida has previously been included in five different genera (Ustilago, Urocystis, Sorosporium, Cintractia, and Tolyposporium), however, molecular analyses revealed that this smut does not belong to any of these genera and represents a distinct ustilaginalean lineage. The closest known phylogenetic relative of Ustilago solida is Heterotolyposporium lepidospermatis, the type species of the monotypic genus Heterotolyposporium. Both smuts differ considerably in both LSU sequences and in several morphological traits, such as the structure of sori and the characteristics of spore balls. Accordingly, the new genus Shivasia is described to accommodate Ustilago solida. This smut infects different Schoenus species (Cyperaceae) in Australia and New Zealand. The description of Shivasia increases the number of endemic smut genera in Australasia to ten. Compared to all other continents the number of endemic smut genera is exceptionally high, which may point at fast evolving characters and/or may be caused by the regional history, including the long-term geographic isolation of Australasia.

Expanding evolutionary diversity in the Ustilaginomycotina: Fereydouniaceae fam. nov. and Fereydounia gen. nov., the first urocystidalean yeast lineage

The systematic position of two strains of a yeast-like fungus isolated from plant remnants on the Kharg Island in the Persian Gulf of Iran is evaluated using morphological, physiological and phylogenetic analyses. In culture, this fungus produced cylindrical cells that reproduced by polar budding on short stalks. Production of ballistoconidia and blastospores was observed. The carbon source assimilation spectrum was broad, but fermentation ability was absent. Phylogenetic analyses of the nuclear SSU, LSU (D1/D2 domain), and ITS rDNA revealed that this fungus represents a new lineage in the Urocystidales of the subphylum Ustilaginomycotina. Based on the comparison of phenotypic characters, physiology, and DNA sequences, a new genus and species Fereydounia khargensis (IBRC-M 30116T = CBS 13305T) is described for this fungus and accommodated in the novel family Fereydouniaceae. This is the first report of anamorphic saprobic fungus residing in the Urocystidales, stressing the remarkable evolutionary diversity in the subphylum Ustilaginomycotina.

Discovery of Thecaphora schwarzmaniana on Rheum ribes in Iran and Turkey: implications for the diversity and phylogeny of leaf smuts on rhubarbs

A leaf smut discovered on wild rhubarb Rheum ribes in Iran and Turkey is evaluated to identify the species. Based on morphological analyses using light and scanning electron microscopy and molecular phylogenetic analyses using ITS and LSU ribosomal DNA sequences, it is shown that the smut fungus belongs to Thecaphora schwarzmaniana, a rare species previously known on Rheum cordatum, R. lobatum, R. macrocarpum, and R. turkestanicum in some central Asian countries. This is the first documented case of Thecaphora schwarzmaniana on Rheum ribes and significantly expands the range of the species on the Asian continent. The ITS and LSU sequences of the Iranian and Turkish material differed from sequences of Thecaphora schwarzmaniana from Rheum palmatum from China. The re-study of the morphology of the respective specimen revealed morphological differences allowing the conclusion that Thecaphora on Rheum palmatum belongs to a distinct species. The new species is not described here due to the paucity of available material. Molecular phylogenetic analyses, based on ITS and LSU sequences, recovered Thecaphora on Rheum spp. in a clade including species on host plants from diverse unrelated families, indicating that multiple inter-family host jumps took place in the course of evolution of Thecaphora species. Vast similarity of ITS and LSU sequences of Thecaphora spp. on Rheum spp. point to their close relation suggesting that co-evolution could shape the diversification of Thecaphora species on Polygonaceae following an initial host jump from another host plant family.

Microbotryum silenes-saxifragae sp. nov. sporulating in the anthers of Silene saxifraga in southern European mountains.

Currently, the monophyletic lineage of anther smuts on Caryophyllaceae includes 22 species classified in the genus Microbotryum. They are model organisms studied in many disciplines of fungal biology. A molecular phylogenetic approach was used to resolve species boundaries within the caryophyllaceous anther smuts, as species delimitation based solely on phenotypic characters was problematic. Several cryptic species were found amongst the anther smuts on Caryophyllaceae, although some morphologically distinct species were discernible, and most species were characterized by high host-specificity. In this study, anther smut specimens infecting Silene saxifraga were analysed using rDNA sequences (ITS and LSU) and morphology to resolve their specific status and to discuss their phylogenetic position within the lineage of caryophyllaceous anther smuts. The molecular phylogeny revealed that all specimens form a monophyletic lineage that is supported by the morphological trait of reticulate spores with tuberculate interspaces (observed in certain spores). This lineage cannot be attributed to any of the previously described species, and the anther smut on Silene saxifraga is described and illustrated here as a new species, Microbotryum silenes-saxifragae. This species clusters in a clade that includes Microbotryum species, which infect both closely and distantly related host plants growing in diverse ecological habitats. It appears possible that host shifts combined with changes to ecological host niches drove the evolution of Microbotryum species within this clade.

Anthracoidea caricis-meadii is a new North American smut fungus on Carex sect. Paniceae

The morphology and phylogeny of Anthracoidea on Carex meadii (sect. Paniceae) collected in Illinois, Iowa, Wisconsin, USA, were studied by light microscopy, scanning electron microscopy and LSU rDNA sequence analyses. As a result A. caricis-meadii sp. nov. is described. The fungus differs morphologically from Anthracoidea laxae and A. paniceae, which also occur on sedges from the section Paniceae. Molecular analyses support the placement of the latter species and Anthracoidea caricis-meadii in different phylogenetic lineages. Because of morphological discrepancies in the literature, A. laxae and A. paniceae also are described and illustrated based on re-examination of respective holotype and isotype specimens.