title: Evaluation of Erysiphe graminis f sp tritici field isolates for resistance to strobilurin fungicides with different SNP detection systems.
abstract: A single nucleotide polymorphism (snp) in the cytochrome b gene confers resistance to strobilurin fungicides in Erysiphe graminis DC fsp tritici Marchal. On the basis of this point mutation three different types of molecular markers have been developed. Cleaved amplified polymorphic sequences and allele-specific PCR were used to score resistant and sensitive isolates from specifically selected regional populations across Europe. The results of molecular tests were in total agreement with the resistance phenotypes revealed by in vivo tests. Serial dilutions of mixed samples (resistant/sensitive) delimited the detection for strobilurin-resistant alleles to a range of 10-50% for both marker classes. Due to these detection limits no mixture of mitochondria within individual isolates was found. Denaturing high performance chromatography was used to increase the detection sensitivity for the mutant allele. Although the detection limit was lowered to 5-10%, there was no evidence for the existence of mixed mitochondrial genotypes.
authors.affiliation: Department of Plant Sciences, Center of Life and Food Sciences Weihenstephan, Technical University Munich, D-85350 Freising, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bäumler
authors.forename: Helge
authors.initials: H
authors.lastname: Sierotzki
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gisi
authors.forename: Volker
authors.initials: V
authors.lastname: Mohler
authors.forename: Friedrich G
authors.initials: FG
authors.lastname: Felsenstein
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schwarz
mesh_terms: D025141:Drug Resistance, Fungal / Q000235:genetics*; D005658:Fungi / Q000187:drug effects* / Q000235:genetics*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D005800:Genes, Fungal / Q000235:genetics; D010641:Phenotype; D017354:Point Mutation / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: D005659:Fungicides, Industrial