Evaluation of Promising Spring Durum Wheat Accessions from the Federal Agricultural Research Center of the Southeast for Resistance to Leaf and Stem Diseases

Field studies were conducted in 2021–2023 in the Saratov and Leningrad regions to identify spring durum wheat accessions resistant to a complex of leaf and stem diseases and carrying the recessive tsn1 allele for the further use in breeding programs. In total, 16 accessions were evaluated. Plant resistance to pathogens causing leaf rust, stem rust, and Septoria diseases was assessed based on the response type (scores) and disease severity (%). The most promising varieties for breeding were: 1) Annushka (moderately resistant to Puccinia triticina (1–2 scores) and P. graminis (2 scores), resistant to Parastagonospora nodorum and Septoria triticicola (12 and 20% disease severity, respectively), and highly resistant to P. pseudonodorum (10% disease severity)); 2) Gala (moderately resistant to P. triticina and P. graminis (2 scores each), resistant to P. nodorum (20% disease severity), and highly resistant to P. pseudonodorum (10% disease severity)); 3) Elizavetinskaya (moderately resistant to P. triticina (2 scores), resistant to Zymoseptoria tritici and P. pseudonodorum (20 and 16% of disease severity, respectively), and highly resistant to P. nodorum (10% disease severity)); 4) Luch 25 (moderately resistant to P. triticina (1–2 scores) and P. graminis (2 scores) and resistant to S. triticicola (16% disease severity)); 5) Nik (moderately resistant to P. triticina (2 scores) and resistant to P. pseudonodorum (16% disease severity)); 6–8) Saratovskaya zolotistaya, Pamyati Vasilchuka, and Tamara (response scores for P. triticina were 1 (resistant), 1–2 (moderately resistant), and 1–2, respectively, resistant to P. graminis (2 scores for all three accessions); and 9) Nikolasha (moderately resistant to P. triticina (2 scores) and resistant to P. nodorum (16% disease severity). Molecular screening revealed the presence of the recessive tsn1 allele, conferring resistance to the SnToxA toxin produced by P. nodorum and P. pseudonodorum, in the varieties Saratovskaya zolotistaya, Valentina, Annushka, Luch 25, Pamyati Vasilchuka, Tamara, and Gala.