Prebreeding studies of spring bread wheat lines, carrying Т1BS.1BL-1S#F7L-1BL translocation with Lr51 gene

One of the sources of bread wheat resistance to the Puccinia triticina is the Lr51 gene in the T1BS.1BL-1S#F7L-1BL translocation, from Aegilops speltoides Tausch. However, it is little used in the practical breeding of Triticum aestivum L. The main reason is the fear of the negative impact of translocation on important agronomic features. This paper presents the results of pre-breeding studies of lines-analogues of spring bread wheat cultivar Saratovskaya 68 - L6 and L7, carrying T1BS.1BL-1S#F7L-1BL translocation, compared with the recipient - Saratovskaya 68 and the standard - Saratovskaya 76. The presence of the Lr51 gene was confirmed by PCR analysis with markers S30-13L and AGA7-759R. Lines L6 and L7 are resistant to saratov populations of P. triticina. The lines-analogues are cytologically stable. The presence of translocation in L6 and L7 did not significantly influence for plant height and lodging resistance. In lines-analogues, the duration of the germination-earing period is at the level of recipient and standard cultivars. For grain productivity, lines L6 and L7 do not significantly differ from Saratovskaya 68. However, lines L6 and L7 surpassed Saratovskaya 76 in 2024, but there were no differences for 2023-2025 period. Analysis of the structure of the elements productivity of the main ear for average 2023-2025 period showed that at the lines L6 and L7 no differences with the cultivar-recipient for all traits. But comparisons with Saratovskaya 76, show significant differences in favor of lines with translocation in terms of ear density, while L7 also had significant differences for grain weight from the ear and number grains in spikelet.The presence of the T1BS.1BL-1S#F7L-1BL translocation in L6 and L7 did not significantly affect the protein content, as well as the indicators of flour and bread, except for the volume and porosity of bread. Lines L6 and L7 were inferior to Saratovskaya 76 in terms of elasticity, the ratio of elasticity to extensibility (P/L), and the volume of bread, but surpassed the strength of flour (W). In general, in terms of cytological stability and the entire range of breeding-valuable indicators, the effect of T1BS.1BL-1S#F7L-1BL translocation in the genotype of the Saratovskaya 68 is assessed as neutral, and lines L6 and L7 have breeding significance for leaf rust resistance.