title: Molecular markers for tracking the origin and worldwide distribution of invasive strains of Puccinia striiformis.
abstract: Investigating the origin and dispersal pathways is instrumental to mitigate threats and economic and environmental consequences of invasive crop pathogens. In the case of Puccinia striiformis causing yellow rust on wheat, a number of economically important invasions have been reported, e.g., the spreading of two aggressive and high temperature adapted strains to three continents since 2000. The combination of sequence-characterized amplified region (SCAR) markers, which were developed from two specific AFLP fragments, differentiated the two invasive strains, PstS1 and PstS2 from all other P. striiformis strains investigated at a worldwide level. The application of the SCAR markers on 566 isolates showed that PstS1 was present in East Africa in the early 1980s and then detected in the Americas in 2000 and in Australia in 2002. PstS2 which evolved from PstS1 became widespread in the Middle East and Central Asia. In 2000, PstS2 was detected in Europe, where it never became prevalent. Additional SSR genotyping and virulence phenotyping revealed 10 and six variants, respectively, within PstS1 and PstS2, demonstrating the evolutionary potential of the pathogen. Overall, the results suggested East Africa as the most plausible origin of the two invasive strains. The SCAR markers developed in the present study provide a rapid, inexpensive, and efficient tool to track the distribution of P. striiformis invasive strains, PstS1 and PstS2.
authors.affiliation: Department of Agroecology Aarhus University Flakkebjerg DK-4200 Slagelse Denmark.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Walter
authors.affiliation: Department of Agroecology Aarhus University Flakkebjerg DK-4200 Slagelse Denmark; Institute of Biotechnology & Genetic Engineering The University of Agriculture, Peshawar 25000 Peshawar Pakistan.
authors.forename: Sajid
authors.initials: S
authors.lastname: Ali
authors.affiliation: The Sainsbury Laboratory Norwich Research Park Norwich NR4 7UH UK; Present address: Eric Kemen Max Planck Institute for Plant Breeding Research Carl-von-Linné-Weg 1050829 Cologne Germany.
authors.forename: Eric
authors.initials: E
authors.lastname: Kemen
authors.affiliation: ICARDA Regional Cereal Rust Research Centre Aegean Agricultural Research Institute P.K. 9 Menemen/İZMİR Turkey.
authors.forename: Kumarse
authors.initials: K
authors.lastname: Nazari
authors.affiliation: National Institute of Agronomy of Tunisia (INAT) Avenue Charles Nicolle 43 TN-1082 El Mahrajène Tunisia.
authors.forename: Bochra A
authors.initials: BA
authors.lastname: Bahri
authors.affiliation: INRA UMR 320 Génétique Végétale Ferme du Moulon F-91190 Gif sur Yvette France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Enjalbert
authors.affiliation: Department of Agroecology Aarhus University Flakkebjerg DK-4200 Slagelse Denmark.
authors.forename: Jens G
authors.initials: JG
authors.lastname: Hansen
authors.affiliation: John Innes Centre Norwich Research Park Norwich NR4 7UH UK.
authors.forename: James K M
authors.initials: JK
authors.lastname: Brown
authors.affiliation: Center for Biological Sequence Analysis Department of Systems Biology Technical University of Denmark Building 208 DK-2800 Kongens Lyngby Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sicheritz-Pontén
authors.affiliation: The Sainsbury Laboratory Norwich Research Park Norwich NR4 7UH UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jones
authors.affiliation: INRA UR 1290 BIOGER-CPP BP01 F-78850 Thiverval-Grignon France.
authors.forename: Claude
authors.initials: C
authors.lastname: de Vallavieille-Pope
authors.affiliation: Department of Agroecology Aarhus University Flakkebjerg DK-4200 Slagelse Denmark.
authors.forename: Mogens S
authors.initials: MS
authors.lastname: Hovmøller
authors.affiliation: Department of Agroecology Aarhus University Flakkebjerg DK-4200 Slagelse Denmark.
authors.forename: Annemarie F
authors.initials: AF
authors.lastname: Justesen
keywords: Aggressive strain; PCR‐based markers; plant pathogen; wheat yellow rust/stripe rust