Phytopathological testing of flax genotypes for anthracnose resistance

Among the large number of harmful and common fungal diseases of flax, anthracnose is one of the dominant ones. There are no highly resistant varieties to this pathogen in production. The search and formation of a collection of diverse sustainable flax material is one of the tasks of the modern selection, which was the purpose of our work. Laboratory and field studies using a synthetic population of anthracnose pathogen to determine flax resistance to the pathogen were conducted in the Northwest area of the Tver region. The object of research were collection samples from the “National Collection of Russian flax” of the Federal Research Center for Bast Crops, flax selection lines obtained by biotechnology and the bio samples of the anthracnose pathogen from the “Collection of microorganisms - pathogens of major flax diseases”. Over the years of research (2019–2023), the "Collection of microorganisms - pathogens of flax diseases" has been replenished with 41 biological samples of the anthracnose pathogen. The dominant position was occupied by highly virulent strains – 55.6%, weakly virulent biological samples made up 18.4%. Screening of 384 collection flax samples against an infectious background revealed a low content of resistant samples, only 36 samples were relatively resistant (50.0–68.0%), and 90.6% of the collection samples were susceptible. 7 genotypes were identified, showing relative resistance to the pathogen at the level of 60.1–68.0%: G-60505-9, D238/2/15/119-13, D14/No.3896hAR6, L-2897-6-6, 0-15247-6-13, 0-15157-7-5, K-3774*. The breeding lines NP r -1-7 and NP r -2-3 of fiber flax, obtained as a result of using biotechnological methods, have confirmed their resistance against an infectious background, in the field (61.1–75.0%). No highly resistant flax samples to anthracnose have been identified. The use of 9 sources characterized by resistance at the level of 60.1–75.0% in the breeding program will increase the efficiency of breeding work to create disease-resistant flax varieties.