Study of culture filtrates of anthracnose pathogen strains for use in in vitro flax breeding for pathogen resistance

Abstract

 The studies were carried out on the basis of the laboratory of breeding technologies of the Federal State Budgetary Scientific Institution “Federal Scientific Center for Bast Crops” (Tver region) in 2018–2020. The aim of the research is to create in vitro new flax genotypes, resistant to anthracnose, one of the most harmful fungal diseases. As a result of the research, the composition of the culture filtrate of the anthracnose causative agent was clarified. It was revealed that the toxicity of the culture filtrates did not depend on the virulence of the strains used in the present studies — the cultural filtrates of strains 784 (highly virulent) and 780 (medium virulent) were more toxic (decay and death of primary roots on day 5 was observed in 67–88% grown seeds), strains 793 (strongly virulent) and 788 (weakly virulent) are less toxic (on the 5th day, decay and death of primary roots was noted in 9–15% of germinated seeds). It was found that morphogenic foci were formed more actively in genotypes, the morphogenic callus of which was transferred to a medium with a higher concentration of the culture filtrate; it was shown that in the second passage, when transferring morphogenic callus from a selective medium containing 40 ml/l of culture filtrate to a selective medium, containing also 40 ml/l of culture filtrate, as well as when transferring morphogenic callus from a selective medium containing 40 ml/l of culture filtrate, on a selective medium, containing 44 ml/l of culture filtrate, on the 14th day the number of formed morphogenic callus and green buds is significantly greater than when transferred from a selective medium, containing 40 ml/l of culture filtrate to a selective medium, containing 36 ml/l of culture filtrate. Viable regenerant plants were obtained and genotypes were isolated, which for three generations retained resistance to anthracnose at a level of 50–60%: NO-78 x Lenok, HJI-103-2 x Lenok, NL-40-1 x Lenok, NE -38 x Rosinka, NE-36 x Lenok, NE-17 x Lenok, HE-16-2 x Rosinka.