Archivio Journal of Plant Pathology

Abstract:

Populations of the potato and tomato late blight pathogen from different regions of the European part of Russia were studied for their genotypic structure and metalaxyl resistance. The majority of the studied populations showed a high genotypic diversity, i.e. strains of A1 and A2 mating types, Ia and IIa mitochondrial DNA haplotypes, and different genotypes at Pep1 and Pep2 loci were identified. The highest genotypic diversity was registered among P. infestans populations from the North Caucasus, Mariy El Republic, and the Moscow region. The obtained data confirm a high probability of crossing and hybridization within the most part of the field populations of P. infestans from the European part of Russia. Most of the studied populations included strains with high and low metalaxyl resistance, the incidence of resistant strains depending on the use of metalaxyl-containing fungicides.