title: Pyricularia graminis-tritici, a newPyriculariaspecies causing wheat blast.
abstract: Pyricularia oryzaeis a species complex that causes blast disease on more than 50 species of poaceous plants.Pyricularia oryzaehas a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates ofP. oryzaesampled from sympatric populations of wheat, rice, and grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogenP. oryzaepathotypeOryza(PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogenP. oryzaepathotypeTriticum(PoT). Clade 3 contained isolates obtained from wheat as well as otherPoaceaehosts. We found that Clade 3 is distinct fromP. oryzaeand represents a new species,Pyricularia graminis-tritici(Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive onTriticum aestivum(wheat),Hordeum vulgare(barley),Urochloa brizantha(signal grass), andAvena sativa(oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associatedPoaceaehosts in Brazil is caused by multiplePyriculariaspecies.Pyricularia graminis-triticiwas recently found causing wheat blast in Bangladesh. This indicates thatP. graminis-triticirepresents a serious threat to wheat cultivation globally.
authors.affiliation: Department of Phytopathology, Rural Engineering, and Soil Science (Departamento de Fitossanidade, Engenharia Rural e Solos), UNESP- University of São Paulo State, Ilha Solteira, São Paulo, Brazil.
authors.forename: V L
authors.initials: VL
authors.lastname: Castroagudín
authors.affiliation: Department of Phytopathology, Federal University of Lavras, Lavras, Minas Gerais, Brazil.
authors.forename: S I
authors.initials: SI
authors.lastname: Moreira
authors.affiliation: Department of Phytopathology, Rural Engineering, and Soil Science (Departamento de Fitossanidade, Engenharia Rural e Solos), UNESP- University of São Paulo State, Ilha Solteira, São Paulo, Brazil;; Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: D A S
authors.initials: DA
authors.lastname: Pereira
authors.affiliation: Department of Phytopathology, Rural Engineering, and Soil Science (Departamento de Fitossanidade, Engenharia Rural e Solos), UNESP- University of São Paulo State, Ilha Solteira, São Paulo, Brazil.
authors.forename: S S
authors.initials: SS
authors.lastname: Moreira
authors.affiliation: Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: P C
authors.initials: PC
authors.lastname: Brunner
authors.affiliation: Brazilian Agriculture Research Corporation-Wheat (EMBRAPA-Trigo), Passo Fundo, Rio Grande do Sul, Brazil.
authors.forename: J L N
authors.initials: JL
authors.lastname: Maciel
authors.affiliation: CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.; Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa.; Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: P W
authors.initials: PW
authors.lastname: Crous
authors.affiliation: Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: B A
authors.initials: BA
authors.lastname: McDonald
authors.affiliation: Department of Phytopathology, Federal University of Lavras, Lavras, Minas Gerais, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Alves
authors.affiliation: Department of Phytopathology, Rural Engineering, and Soil Science (Departamento de Fitossanidade, Engenharia Rural e Solos), UNESP- University of São Paulo State, Ilha Solteira, São Paulo, Brazil.
authors.forename: P C
authors.initials: PC
authors.lastname: Ceresini
keywords: Triticum aestivum; cryptic species; host adaptation; phylogenetics; systematics