Fungal systematics and evolution最新文献

The downy mildew species parasitic to Mentheae are of particular interest, as this tribe of Lamiaceae contains a variety of important medicinal plants and culinary herbs. Over the past two decades, two pathogens, Peronospora belbahrii and Pe. salviae-officinalis have spread globally, impacting basil and common sage production, respectively. In the original circumscription of Pe. belbahrii, the downy mildew of coleus (Plectranthus scutellarioides) was ascribed to this species in the broader sense, but subtle differences in morphological and molecular phylogenetic analyses using two genes suggested that this pathogen would potentially need to be assigned to a species of its own. In the present study, Peronospora species causing downy mildew on members of the Mentheae, including clary sage (Salvia sclarea), meadow sage (S. pratensis), basil (Ocimum basilicum), ground ivy (Glechoma hederacea) and coleus (Plectranthus scutellarioides) were studied using light microscopy and molecular phylogenetic analyses based on six loci (ITS rDNA, cox1, cox2, ef1a, hsp90 and β-tubulin) to clarify the species boundaries in the Pe. belbahrii species complex. The downy mildew on Salvia pratensis is shown to be distinct from Pe. salviae-officinalis and closely related to Pe. glechomae, and is herein described as a new species, Pe. salviae-pratensis. The downy mildew on S. sclarea was found to be caused by Pe. salviae-officinalis. This is of phytopathological importance, because meadow sage thus does not play a role as inoculum source for common sage in the natural habitat of the former in Europe and Asia, while clary sage probably does. The multi-gene phylogeny revealed that the causal agent of downy mildew on coleus is distinct from Pe. belbahrii on basil, and is herein described as a new taxon, Pe. choii.

Based on our study of the morphology and genetics of sporocarps collected in the mountains of northern Thailand, we herein describe Entoloma sequestratum as a new sequestrate member of the Entolomotaceae. This serves as the first report of a sequestrate member of the genus from Thailand. In addition, we provide a worldwide key to all of the described sequestrate members of the genus.

The Genera of Fungi series, of which this is the sixth contribution, links type species of fungal genera to their morphology and DNA sequence data. Five genera of microfungi are treated in this study, with new species introduced in Arthrographis, Melnikomyces, and Verruconis. The genus Thysanorea is emended and two new species and nine combinations are proposed. Kramasamuha sibika, the type species of the genus, is provided with DNA sequence data for first time and shown to be a member of Helminthosphaeriaceae (Sordariomycetes). Aureoconidiella is introduced as a new genus representing a new lineage in the Dothideomycetes.

The oomycete genus Ectrogella currently comprises a rather heterogeneous group of obligate endoparasitoids, mostly of diatoms and algae. Despite their widespread occurrence, little is known regarding the phylogenetic affinities of these bizarre organisms. Traditionally, the genus was included within the Saprolegniales, based on zoospore diplanetism and a saprolegnia/achlya-like zoospore discharge. The genus has undergone multiple re-definitions in the past, and has often been used largely indiscriminately for oomycetes forming sausage-like thalli in diatoms. While the phylogenetic affinity of the polyphyletic genus Olpidiopsis has recently been partially resolved, taxonomic placement of the genus Ectrogella remained unresolved, as no sequence data were available for species of this genus. In this study, we report the phylogenetic placement of Ectrogella bacillariacearum infecting the freshwater diatom Nitzschia sigmoidea. The phylogenetic reconstruction shows that Ectrogella bacillariacearum is grouped among the early diverging lineages of the Saprolegniomycetes with high support, and is unrelated to the monophyletic diatom-infecting olpidiopsis-like species. As these species are neither related to Ectrogella, nor to the early diverging lineages of Olpidiopsis s. str. and Miracula, they are placed in a new genus, Diatomophthora, in the present study.

To clarify the diversity of plant-parasitic Alternaria species in Japan, diseased samples were collected, and fungal isolates established in culture. We examined 85 isolates representing 23 species distributed in 14 known sections based on conidial morphology and DNA phylogeny. Three species were found to be new, A. cylindrica, A. paragomphrenae and A. triangularis. Furthermore, a lectotype was designated for A. gomphrenae, and epitypes for A. cinerariae, A. gomphrenae, A. iridicola, and A. japonica. Species boundaries of isolates were also clarified by studying phenotypes and determining host ranges. Alternaria gomphrenae and related species in sect. Alternantherae were recognized as distinct species owing to their host specificity. Among the species infecting Apiaceae, the pathogenicity of A. cumini and a novel species, A. triangularis ex Bupleurum, were confirmed as host specific. Another novel species, A. cylindrica, proved to be host specific to Petunia. Alternaria iridicola was recognized as a large-spored species in sect. Alternaria, being host specific to Iris spp. On the other hand, the experimental host ranges of three morphologically and phylogenetically distinct species infecting Brassicaceae (A. brassicae, A. brassicicola, and A. japonica) showed almost no differences. Alternaria brassicicola and A. porri were even found on non-host plants. In general, host ranges of Alternaria species correlated with morphology and molecular phylogeny, and combining these datasets resulted in clearer species boundaries.

The present paper represents the fifth contribution in the Genera of Fungi series, linking type species of fungal genera to their morphology and DNA sequence data. This paper focuses on 11 genera of microfungi, for seven of which the type species are neo- or epitypified here: Arthrinium (Arthrinium caricicola; Apiosporaceae, Xylariales, Sordariomycetes), Ceratosphaeria (Ceratosphaeria lampadophora; Magnaporthaceae, Magnaporthales, Sordariomycetes), Dimerosporiopsis (Dimerosporiopsis engleriana; Venturiaceae, Venturiales, Dothideomycetes), Hormodochis (Hormodochis melanochlora; Stictidaceae, Ostropales, Ostropomycetidae, OSLEUM clade, Lecanoromycetes), Lecanostictopsis (Lecanostictopsis kamatii; Mycosphaerellaceae, Capnodiales, Dothideomycetes), Lembosina (Lembosina aulographoides; Lembosinaceae fam. nov., Lembosinales ord. nov., Dothideomycetes), Neomelanconium (Neomelanconium gelatosporum; Cenangiaceae, Helotiales, Leotiomycetes), Phragmotrichum (Phragmotrichum chailletii; Melanommataceae, Pleosporales, Pleosporomycetidae, Dothideomycetes), Pseudomelanconium gen. nov. (Pseudomelanconium spartii; incertae sedis, Pezizomycotina), Rutola (Rutola graminis; Torulaceae, Pleosporales, Pleosporomycetidae, Dothideomycetes), and Trullula (Trullula oreoselini; incertae sedis, Pezizomycotina).

Our understanding of the systematics of red yeasts has greatly improved with the availability of sequence data and it is now clear that the majority of these fungi belong to three different classes of Pucciniomycotina (Basidiomycota): Agaricostilbomycetes, Cystobasidiomycetes, and Microbotryomycetes. Despite improvements in phylogenetic placement, the taxonomy of these fungi has long been in need of revision and still has not been entirely resolved, partly due to missing taxa. In the present study, we present data of culture-based environmental yeast isolation, revealing several undescribed species of Symmetrospora, which was recently introduced to accommodate six species previously placed in the asexual genera Sporobolomyces and Rhodotorula in the gracilis/marina clade of Cystobasidiomycetes. Based on molecular phylogenetic analyses of three rDNA loci, morphology, and biochemical studies, we formally describe the following new species: Symmetrospora clarorosea sp. nov. from leaf surfaces in Portugal and the USA; S. pseudomarina sp. nov. from leaf surfaces in Brazil, and the USA and decaying wood in the USA; and S. suhii sp. nov. from a beetle gut in the USA, leaf surfaces in Brazil and marine water in the Taiwan and Thailand. Finally, we propose a new combination for Sporobolomyces oryzicola based on our molecular phylogenetic data, Symmetrospora oryzicola comb. nov.

Geodina salmonicolor is shown to be a synonym of G. guanacastensis, the type and only species of the genus. Comparisons of ITS rDNA sequences of a paratype and two recent collections of G. guanacastensis with published ITS sequences of G. salmonicolor, from the Dominican Republic, show that these are nearly identical. When G. salmonicolor was erected no sequences of the type species were available. Morphological comparisons supports the conspecificity. Details regarding the description of G. salmonicolor are pointed out. A four-gene phylogeny places Geodina and Wynnea as a supported sister group to the rest of the Sarcoscyphaceae. Species in these genera share morphological traits of cyanophobic spore markings, dark angular outer excipular cells that give rise to hairs and the origin of several apothecia from a common basal stalk. Their occurrence on soil rather than on wood or plant material distinguish them from other Sarcoscyphaceae. Based on morphology, phylogenic relationships and trophic interactions we erect a new family, Wynneaceae, for Geodina and Wynnea.

During the last decade, the classification system of chytrids has dramatically changed based on zoospore ultrastructure and molecular phylogeny. In contrast to well-studied saprotrophic chytrids, most parasitic chytrids have thus far been only morphologically described by light microscopy, hence they hold great potential for filling some of the existing gaps in the current classification of chytrids. The genus Zygorhizidium is characterized by an operculate zoosporangium and a resting spore formed as a result of sexual reproduction in which a male thallus and female thallus fuse via a conjugation tube. All described species of Zygorhizidium are parasites of algae and their taxonomic positions remain to be resolved. Here, we examined morphology, zoospore ultrastructure, host specificity, and molecular phylogeny of seven cultures of Zygorhizidium spp. Based on thallus morphology and host specificity, one culture was identified as Z. willei parasitic on zygnematophycean green algae, whereas the others were identified as parasites of diatoms, Z. asterionellae on Asterionella, Z. melosirae on Aulacoseira, and Z. planktonicum on Ulnaria (formerly Synedra). According to phylogenetic analysis, Zygorhizidium was separated into two distinct order-level novel lineages; one lineage was composed singly of Z. willei, which is the type species of the genus, and the other included the three species of diatom parasites. Zoospore ultrastructural observation revealed that the two lineages can be distinguished from each other and both possess unique characters among the known orders within the Chytridiomycetes. Based on these results, we accommodate the three diatom parasites, Z. asterionellae, Z. melosirae, and Z. planktonicum in the distinct genus Zygophlyctis, and propose two new orders: Zygorhizidiales and Zygophlyctidales.