title: Genetic diversity and occurrence of the F129L substitutions among isolates ofAlternaria solaniin south-eastern Sweden.
abstract: BACKGROUND
  Early blight, caused by the fungusAlternaria solani,occurs on potato mainly in the south-eastern part of Sweden, but also in other parts of the country. The aim of this study was to investigate the genetic diversity ofA. solanipopulations from different potato growing regions in south-eastern Sweden using AFLP marker analysis. In addition, the cultured isolates were examined for substitutions in the gene encoding cytochromeb, associated with loss of sensitivity against QoI fungicides.
  
  
  RESULTS
  Nei's gene diversity index for the Swedish populations ofA. solanirevealed a gene diversity of up to 0.20. Also genetic differentiation was observed among populations ofA. solanifrom different locations in south-eastern Sweden. The mitochondrial genotype of the isolates ofA. solaniwas determined and both known genotypes, GI (genotype 1) and GII (genotype 2), were found among the isolates. The occurrence of the F129L substitution associated with a loss of sensitivity to strobilurins was confirmed among the GII isolates. In vitro conidial germination tests verified that isolates containing the F129L substitution had reduced sensitivity to azoxystrobin and, at a lower extent, to pyraclostrobin.
  
  
  CONCLUSIONS
  Genetic diversity was relatively high among isolates ofA. solaniin south-eastern part of Sweden. F129L substitutions, leading to reduced sensitivity to strobilurins, have been established in field populations, which may have implications for the future efficacy of QoI fungicides.
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, SE-230 53 Alnarp, Sweden.
authors.forename: Firuz
authors.initials: F
authors.lastname: Odilbekov
authors.affiliation: Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-750 07 Uppsala, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Edin
authors.affiliation: Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box, 101, SE-230 53 Alnarp, Sweden.
authors.forename: Larisa
authors.initials: L
authors.lastname: Garkava-Gustavsson
authors.affiliation: Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box, 101, SE-230 53 Alnarp, Sweden.
authors.forename: Helena Persson
authors.initials: HP
authors.lastname: Hovmalm
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, SE-230 53 Alnarp, Sweden.
authors.forename: Erland
authors.initials: E
authors.lastname: Liljeroth
mesh_terms: D000528:Alternaria / Q000187:drug effects / Q000235:genetics*; D054458:Amplified Fragment Length Polymorphism Analysis; D002219:Carbamates / Q000494:pharmacology; D045303:Cytochromes b / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics*; D005659:Fungicides, Industrial / Q000494:pharmacology; D014644:Genetic Variation; D005838:Genotype; D008689:Methacrylates / Q000494:pharmacology; D008928:Mitochondria / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D011198:Solanum tuberosum / Q000382:microbiology; D000073739:Strobilurins; D013548:Sweden
chemical_list: D002219:Carbamates; D004271:DNA, Fungal; D005659:Fungicides, Industrial; D008689:Methacrylates; D011720:Pyrazoles; D011743:Pyrimidines; D000073739:Strobilurins; D045303:Cytochromes b; C513428:pyrachlostrobin; C087670:azoxystrobin
keywords: AFLP; Early blight; Potato; Sensitivity; Strobilurin