Changes in the Structure of Phytophthora infestans Population in the West Part of the Moscow Region in 2018–2020 According to Phytopathological and Molecular Data

ABSTRACT

Late blight, caused by the oomycete Phytophthora infestans, is one of the most important potato diseases. The increased epidemiological potential of P. infestans has caused a sharp decrease in the effectiveness of previously adopted potato protection methods, including the cultivation of resistant varieties and biological and chemical protection. A set of 12 simple‐sequence repeat (SSR) markers is traditionally used for genotyping P. infestans , allowing comparison of pathogen populations collected in different parts of the world. The objective of this study was to investigate the polymorphism of P. infestans based on 12 SSR markers at one site for 3 years and compare the results of molecular studies with such phenotypic characteristics as mating type, resistance to metalaxyl and virulence. We studied 55 isolates of P. infestans collected from potato varieties and interspecific hybrids in the field from 2018 to 2020. We obtained data on the polymorphism of populations, identified dominant clonal lines and showed that populations in the Moscow region have high polymorphism, and the dominant clonal line of P. infestans changes every year. Comparison of our results with data from other researchers indicates significant differences in the SSR profiles of P. infestans genotypes identified in the European territory of Russia and in Europe.