Evolution of virulence in population of flax rust pathogen Melampsora lini (Pers.) Lev. in conditions of Russia

Abstract

Background. Rust is a dangerous flax disease, which reduces the yield and quality of products. The choice of methods of breeding for resistance should be based on knowledge of the processes occurring in the fungi population, and leading to changes in its virulence. Materials and methods. The article describes the results of over then 40 years observation of the flax rust pathogen Melampsora lini (Pers.) Lev. populations’ virulence during the study of resistance of accessions from VIR world flax collection on artificial infectious background. Late sparse sowings were infected by last year’s infected with fungi straw. The method of this background creation allows one to maintain a natural flow of race-forming process. Results. Susceptibility of 45 relatively resistant accessions from 1978 to 2011 is presented. The significant narrowing of the fungi populations’ virulence, caused by the spread in flax sowing zone cultivars with polygenic resistance, providing a calm epidemiological situation for several decades, was shown. Now under the influence of the distribution of varieties with different types of resistance, fungi turned into depression. Conclusion. The modern trend of breeding, mainly aimed at the creation of varieties with vertical resistance, and in the absence of control over the originality of their R-genes can lead to a new round of the disease development.

Keywords

Linum usitatissimum / Melampsora lini (M. lini) / Linum usitatissimum / Melampsora lini / populations’ virulence / infectious background / resistance genes / polygenic resistance

RIGHTS & PERMISSIONS

Kutuzova S.N., Porokhovinova E.A., Brutch N.B.