The development of the initial material of spring common wheat for breeding for resistance to stem rust ( Puccinia graminis Pers. f. sp. tritici ), including the Ug99 race, in Russia

The donors of resistance of common wheat to the stem rust race Ug99 (breeding lines GT96/90, 113/00i-4, and 119/4-06rw) are involved in cross breeding with the use of the step-crossing and backcrossing methods. While developing hybrids with the spring mode of life, the donor of resistance 113/00i-4 ( Sr2, Sr36, Sr39, Sr40, Sr44, Sr47 ) and accession 145/05i, which is resistant to leaf rust under the conditions prevalent in Russia’s Central Region but susceptible to Ug99, were used. From the obtained hybrid F 4 –F 5 families and backcross progeny BC 1 F 3 -BC 2 F 2 -BC 3 F 2 , 137 individual plants with the homozygotic state of the alleles of 2–5 resistance genes to stem rust were selected by molecular markers. The progeny of these individual plants was tested in the North Caucasian and West Siberian regions of Russia for natural populations of stem and leaf rust and for powdery mildew in the Central Region. The lines resistant to these diseases were estimated for other economically valuable features: plant height, number of days before heading, ear productivity, weight of 1000 grains, and the protein and gluten content in the grain. The 71 spring wheat lines with multiple resistance to two or three diseases and the development of the best agronomic characteristics were selected for the Central Region and 20 lines were selected for West Siberia for further testing their competitiveness with the best varieties and lines in the breeding nurseries. As a result of the work, original source material was developed with several spring wheat resistance genes to Ug99.