title: AFLP and phylogenetic analyses of North American and European populations of Phytophthora ramorum.
abstract: The genetic structure within and between USA and European populations of the emerging phytopathogen Phytophthora ramorum was examined. Four primer combinations were used for amplified fragment length polymorphism (AFLP) fingerprinting of 67 USA isolates from California and Oregon, and 18 European isolates from Belgium, Germany, The Netherlands, Spain and the UK. In addition, three DNA regions (ITS, cox II, and nad 5) of additional Phytophthora species were amplified by polymerase chain reaction, sequenced, and analysed to provide better phylogenetic understanding of P. ramorum within the genus Phytophthora. AFLP banding patterns indicate that the 85 isolates form two distinct lineages within a monophyletic group, distinct from the closely related outgroup species P. lateralis. With the exception of two isolates from an Oregon nursery, European and USA isolates clustered separately within individual clades. The AFLP profiles also indicate that a single clonal lineage dominates the North American population, while the European population consists of an array of mainly unique, closely related AFLP types. Sequences from the three DNA regions were identical among all P. ramorum isolates, and phylogenetic analysis indicates that P. ramorum is closely related to P. lateralis and P. hibernalis.
authors.affiliation: Department of Environmental Science, Policy, and Management-Ecosystem Sciences Division, University of California, Berkeley, CA 94720, USA. kivors@nature.berkeley.edu
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Ivors
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Hayden
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Bonants
authors.forename: David M
authors.initials: DM
authors.lastname: Rizzo
authors.forename: Matteo
authors.initials: M
authors.lastname: Garbelotto
mesh_terms: D001483:Base Sequence; D016000:Cluster Analysis; D004247:DNA / Q000737:chemistry / Q000235:genetics; D016172:DNA Fingerprinting; D021901:DNA, Intergenic / Q000737:chemistry / Q000235:genetics; D005060:Europe; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010838:Phytophthora / Q000145:classification / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry / Q000235:genetics; D029963:Quercus; D016415:Sequence Alignment; D014481:United States
chemical_list: D021901:DNA, Intergenic; D024101:Mitochondrial Proteins; D010940:Plant Proteins; D004247:DNA; D011451:Prostaglandin-Endoperoxide Synthases