title: Genetic analysis of Phytophthora infestans populations in the Nordic European countries reveals high genetic variability.
abstract: Late blight, caused by the oomycete Phytophthora infestans, is the most important disease of potato (Solanum tuberosum). The pathogen is highly adaptable and to get an overview of the genetic variation in the Nordic countries, Denmark, Finland, Norway and Sweden we have analyzed 200 isolates from different fields using nine simple-sequence repeat (SSR) markers. Forty-nine alleles were detected among the nine SSR loci and isolates from all four Nordic countries shared the most common alleles across the loci. In total 169 multilocus genotypes (based on seven loci) were identified among 191 isolates. The genotypic diversities, quantified by a normalized Shannon's diversity index (H(s)), were 0.95 for the four Nordic countries. The low F(ST) value of 0.04 indicates that the majority of variation is found within the four Nordic countries. The large number of genotypes and the frequency distribution of mating types (60% A1) support the hypothesis that sexual reproduction is contributing notably to the genetic variation of P. infestans in the Nordic countries.
authors.affiliation: Norwegian Institute for Agricultural and Environmental Research, Plant Health and Plant Protection Division, Bioforsk, Høgskoleveien 7, 1432 Ås, Norway. may.brurberg@bioforsk.no
authors.forename: May Bente
authors.initials: MB
authors.lastname: Brurberg
authors.forename: Abdelhameed
authors.initials: A
authors.lastname: Elameen
authors.forename: Vinh Hong
authors.initials: VH
authors.lastname: Le
authors.forename: Ragnhild
authors.initials: R
authors.lastname: Naerstad
authors.forename: Arne
authors.initials: A
authors.lastname: Hermansen
authors.forename: Ari
authors.initials: A
authors.lastname: Lehtinen
authors.forename: Asko
authors.initials: A
authors.lastname: Hannukkala
authors.forename: Bent
authors.initials: B
authors.lastname: Nielsen
authors.forename: Jens
authors.initials: J
authors.lastname: Hansen
authors.forename: Björn
authors.initials: B
authors.lastname: Andersson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Yuen
mesh_terms: D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D003718:Denmark; D005387:Finland; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D018895:Microsatellite Repeats; D025282:Mycelium / Q000235:genetics*; D009664:Norway; D055750:Phytophthora infestans / Q000235:genetics*; D011198:Solanum tuberosum / Q000382:microbiology; D013548:Sweden
chemical_list: D004271:DNA, Fungal