Identification of effector genes of <i>Parastagonospora nodorum</i>, <i>P. pseudonodorum</i> in Tambov populations and sensitivity genes to NEs in varieties and hybrid lines of spring soft wheat

Abstract

BACKGROUND: Parastagonospora nodorum and P. pseudonodorum are known for their ability to produce necrotrophic effectors that play an important role in micromycete pathogenicity. Fungal strains characterized by the presence of effector genes will be used to create artificial infectious backgrounds to identify sources and donors of resistance to fungal diseases. Selected varieties and lines that are donors of recessive alleles snn1 and snn3, which control plant resistance to fungal toxins PtrTox1 and PtrTox3, are recommended for inclusion in programs for breeding wheat for resistance to septoriosis pathogens. AIM: The aim of the work is to assess the populations of the fungi Parastagonospora nodorum and P. pseudonodorum in 2023 based on the presence of effector genes, as well as to identify alleles of Snn1/snn1, Snn3/snn3 genes that control the sensitivity or resistance of wheat to PtrTox1 and PtrTox3 toxins. MATERIALS AND METHODS: Infectious samples were collected in 2023 from spring wheat leaves. In addition, the material for the study was 2 varieties and 23 lines of spring soft wheat of local selection. Using the molecular markers Xfcp624 and Xcfd20, the presence of the Snn1 and Snn3-B1 alleles, which control sensitivity to the fungal toxins PtrTox1 and PtrTox3, was detected. RESULTS: Using molecular screening, ToxA and Tox1 genes were identified in genotypes of P. pseudonodorum isolates; Tox3 and Tox267 in P. nodorum isolates. 2 varieties of spring soft wheat and 11 hybrid lines carry a recessive allele snn1, which protects against the phytopathogen toxin PtrTox1; wheat variety Tambovchanka and 2 hybrid lines carry the recessive allele snn3 on chromosome B1, which confers resistance to the fungal toxin PtrTox3. CONCLUSIONS: The ToxA gene was found only among monoconidial isolates of P. pseudonodorum species obtained from leaves of spring soft wheat of Lebedushka variety. As a result of molecular screening, the Tox1 gene was identified among 70 P. pseudonodorum isolates (43,21% of those studied). The presence of the Tox3 and Tox267 genes was established in 30 isolates of P. nodorum species obtained from plant samples of spring durum wheat Donskaya Elegiya. Using the PCR method, donors of the snn1 and snn3 genes were identified.