Phylogenetic relationships of Phaeochorella parinarii and recognition of a new family, Phaeochorellaceae (Diaporthales)

A Phylogenetic and Taxonomic Revision of Discula theae-sinensis, the Causal Agents of Anthracnose on Camellia sinensis

Tea (Camellia sinensis (L.) Kuntze) is one of the most important economic plants in China, and has many benefits for human health. Anthracnose is one of the most serious diseases of tea in China, and control of the fungus is important since most Chinese cultivars are susceptible to it. The agent of tea anthracnose was initially described as Gloeosporium theae-sinensis I. Miyake in Japan, which was later transferred to Discula, but this taxonomic position remains problematic. To shed light on these taxonomic and phylogenetic issues, the tea anthracnose pathogens were re-studied. Combining the morphological characteristics and a multigene phylogenetic analysis of nrITS, nrLSU, rpb2, and tef1 sequence data, a new genus Sinodiscula was proposed to accommodate the causal fungi of tea anthracnose, including a new species Sinodiscula camellicola and a new combination Sinodiscula theae-sinensis. Furthermore, the pathogenicity of the pathogens was determined according to Koch's postulates. This study thoroughly resolves the long-standing taxonomic and phylogenetic problems of the tea anthracnose pathogens.

Two new fungal genera (Diaporthales) found on Dipterocarpaceae in Thailand

Diaporthales is a species-rich order of fungi that includes endophytes, saprobes, and pathogens associated with forest plants and crops. They may also occur as parasites or secondary invaders of plant tissues injured or infected by other organisms or inhabit living animal and human tissues, as well as soil. Meanwhile, some severe pathogens wipe out large-scale cultivations of profitable crops, timber monocultures, and forests. Based on morphological and phylogenetic analyses of combined ITS, LSU, tef1-α, and rpb2 sequence data, generated using maximum likelihood (ML), maximum parsimony (MP), and MrBayes (BI), we introduce two new genera of Diaporthales found in Dipterocarpaceae in Thailand, namely Pulvinaticonidioma and Subellipsoidispora. Pulvinaticonidioma is characterized by solitary, subglobose, pycnidial, unilocular conidiomata with the internal layers convex and pulvinate at the base; hyaline, unbranched, septate conidiophores; hyaline, phialidic, cylindrical to ampulliform, determinate conidiogenous cells and hyaline, cylindrical, straight, unicellular, and aseptate conidia with obtuse ends. Subellipsoidispora has clavate to broadly fusoid, short pedicellate asci with an indistinct J- apical ring; biturbinate to subellipsoidal, hyaline to pale brown, smooth, guttulate ascospores that are 1-septate and slightly constricted at the septa. Detailed morphological and phylogenetic comparisons of these two new genera are provided in this study.

Taxonomy and Multigene Phylogeny of Diaporthales in Guizhou Province, China

In a study of fungi isolated from plant material in Guizhou Province, China, we identified 23 strains of Diaporthales belonging to nine species. These are identified from multigene phylogenetic analyses of ITS, LSU, rpb2, tef1, and tub2 gene sequence data coupled with morphological studies. The fungi include a new genus (Pseudomastigosporella) in Foliocryphiaceae isolated from Acer palmatum and Hypericum patulum, a new species of Chrysofolia isolated from Coriaria nepalensis, and five new species of Diaporthe isolated from Juglans regia, Eucommia ulmoides, and Hypericum patulum. Gnomoniopsis rosae and Coniella quercicola are newly recorded species for China.

Molecular reassessment of diaporthalean fungi associated with strawberry, including the leaf blight fungus, Paraphomopsis obscurans gen. et comb. nov. (Melanconiellaceae)

Phytopathogenic fungi in the order Diaporthales (Sordariomycetes) cause diseases on numerous economically important crops worldwide. In this study, we reassessed the diaporthalean species associated with prominent diseases of strawberry, namely leaf blight, leaf blotch, root rot and petiole blight, based on molecular data and morphological characters using fresh and herbarium collections. Combined analyses of four nuclear loci, 28S ribosomal DNA/large subunit rDNA (LSU), ribosomal internal transcribed spacers 1 and 2 with 5.8S ribosomal DNA (ITS), partial sequences of second largest subunit of RNA polymerase II (RPB2) and translation elongation factor 1-α (TEF1), were used to reconstruct a phylogeny for these pathogens. Results confirmed that the leaf blight pathogen formerly known as Phomopsis obscurans belongs in the family Melanconiellaceae and not with Diaporthe (syn. Phomopsis) or any other known genus in the order. A new genus Paraphomopsis is introduced herein with a new combination, Paraphomopsis obscurans, to accommodate the leaf blight fungus. Gnomoniopsis fragariae comb. nov. (Gnomoniaceae), is introduced to accommodate Gnomoniopsis fructicola, the cause of leaf blotch of strawberry. Both of the fungi causing leaf blight and leaf blotch were epitypified. Fresh collections and new molecular data were incorporated for Paragnomonia fragariae (Sydowiellaceae), which causes petiole blight and root rot of strawberry and is distinct from the above taxa. An updated multilocus phylogeny for the Diaporthales is provided with representatives of currently known families.

Reevaluating Cryphonectriaceae and allied families in Diaporthales

The Diaporthales (Sordariomycetes) includes many important families of plant pathogenic fungi, such as the notorious Cryphonectriaceae. The aim of the present study was to reevaluate this family, along with other families in Diaporthales. Based on phylogenetic analyses using combined sequence data of the internal transcribed spacer (ITS) region, large subunit of the nrDNA (28S), and the translation elongation factor 1-alpha (tef1-α) and DNA-directed RNA polymerase II second largest subunit (rpb2) genes, Cryphonectriaceae is separated into two subclades, comprising 21 genera and 55 species. Foliocryphiaceae, fam. nov., is morphologically and phylogenetically its closest relative but is distinct due to its phylogeny and dimorphic conidia. Mastigosporellaceae, fam. nov., is distinguished from other families in Diaporthales by owning apical conidial appendages. Neocryphonectria, gen. nov., within the family Foliocryphiaceae, with two species associated with Carpinus canker in China, is characterized by fusoid, aseptate macroconidia. Additionally, two new combinations are proposed, namely, Cryphonectria citrine, based on Chromendothia citrine, and Cytospora viridistroma, based on Endothia viridistoma. Based on results obtained in this study, 31 families are accepted into Diaporthales.

Diaporthalean fungi associated with canker and dieback of trees from Mount Dongling in Beijing, China

Diaporthales is a fungal order comprising important plant pathogens, saprobes and endophytes on a wide range of woody hosts. It is often difficult to differentiate the pathogens in this order, since both the morphology and disease symptoms are similar among the various species. In the current study, we obtained 15 representative diaporthalean isolates from six tree hosts belonging to plant families Betulaceae, Fagaceae, Juglandaceae, Rosaceae, and Ulmaceae from Mount Dongling in China. Six species were identified residing in four families of Diaporthales (Diaporthaceae, Erythrogloeaceae, Juglanconidaceae and Melanconidaceae). Based on morphological comparison and the phylogenetic analyses of partial ITS, LSU, cal, his3, rpb2, tef1-α and tub2 gene sequences, we identified five known species (Diaporthe betulina, D. eres, D. rostrata, Juglamconis oblonga and Melanconis stilbostoma) and one novel species (Dendrostoma donglinensis). These results represent the first study of diaporthalean fungi associated with canker and dieback symptoms from Mount Dongling in Beijing, China.

Cytospora (Diaporthales) in China

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.