title: Hybridization of powdery mildew strains gives rise to pathogens on novel agricultural crop species.
abstract: Throughout the history of agriculture, many new crop species (polyploids or artificial hybrids) have been introduced to diversify products or to increase yield. However, little is known about how these new crops influence the evolution of new pathogens and diseases. Triticale is an artificial hybrid of wheat and rye, and it was resistant to the fungal pathogen powdery mildew (Blumeria graminis) until 2001 (refs. 1,2,3). We sequenced and compared the genomes of 46 powdery mildew isolates covering several formae speciales. We found that B. graminis f. sp. triticale, which grows on triticale and wheat, is a hybrid between wheat powdery mildew (B. graminis f. sp. tritici) and mildew specialized on rye (B. graminis f. sp. secalis). Our data show that the hybrid of the two mildews specialized on two different hosts can infect the hybrid plant species originating from those two hosts. We conclude that hybridization between mildews specialized on different species is a mechanism of adaptation to new crops introduced by agriculture.
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Fabrizio
authors.identifier: http://orcid.org/0000-0002-7885-4482
authors.initials: F
authors.lastname: Menardo
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Coraline R
authors.initials: CR
authors.lastname: Praz
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wyder
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Roi
authors.initials: R
authors.lastname: Ben-David
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Salim
authors.initials: S
authors.lastname: Bourras
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Matsumae
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Kaitlin E
authors.initials: KE
authors.lastname: McNally
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Francis
authors.initials: F
authors.lastname: Parlange
authors.affiliation: Biozentrum, University of Basel, Basel, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Riba
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Roffler
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Luisa K
authors.initials: LK
authors.lastname: Schaefer
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland.
authors.forename: Kentaro K
authors.initials: KK
authors.lastname: Shimizu
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Luca
authors.initials: L
authors.lastname: Valenti
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Helen
authors.initials: H
authors.lastname: Zbinden
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wicker
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Keller
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics*; D018556:Crops, Agricultural / Q000382:microbiology*; D005800:Genes, Fungal; D013045:Species Specificity