2026/03/01 by Marta Janiszewska, S. Sobkowiak, Sylwester Sobkowiak +4
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Plant Pathogens and Resistance #Powdery Mildew Fungal Diseases #Plant and Fungal Interactions Research
paper · doi:10.1111/ppa.70146
ABSTRACT The objective of this study was to analyse the genetic structure of the population of Phytophthora infestans in Poland, focusing on determining whether seed tubers play a role in pathogen migration and on the role of sexual recombination. In total, 858 isolates were collected from 2016 to 2018, 2020 and 2021 from 10 locations in different regions. The isolates were described in terms of mating type, mitochondrial haplotype, resistance to metalaxyl, virulence and polymorphism at 12 simple‐sequence repeat (SSR) loci. Both mating types were found and often occurred in the same field. Among 858 P. infestans isolates, 309 multilocus genotypes (MLGs) were identified. Almost 24% ( n = 204) of the sampled isolates were classified to European P. infestans genotypes: EU13, EU34, EU41, EU36 and EU37. The remaining 654 isolates of P. infestans had MLGs that were unique to Poland and strongly suggested sexual recombination and oospores as a source of inoculum. In parentage analysis, each European P. infestans genotype tested as a potential parent was assigned a different parent–offspring probability. Probable progeny isolates were identified for genotypes EU13 and EU34, which have been present in the Polish P. infestans population since 2005 and 2002, respectively. Detection of 2–16 P. infestans isolates of Polish genotypes in the same year but in different locations indicates seed potatoes as a migration route for the pathogen. Our study highlights sexual recombination and seed potato‐related migrations as factors affecting the P. infestans population structure in Poland, increasing the pathogen's genetic adaptability.