Resistance to Brown and Stem Rust in Spring Soft Wheat Varieties in the Arid Climate of Northern Kazakhstan

To create competitive wheat varieties, it is essential to make active use of the world's diversity of genetic resources. The study aims to test the genetic resources of spring soft wheat for resistance to rust diseases. A spring soft wheat collection consisting of 206 samples, was studied in 2020-2022 for resistance to leaf and stem rust, as well as for a complex of valuable agronomic traits. The results of the study identify 13 samples resistant to brown rust and stem rust. The variety Weebill 1 (Mexico) had a high resistance to two diseases and the variety Jacui (Brazil) was also characterized by resistance to these diseases. Three varieties are characterized by high yield: CATBIRD (Mexico), Lutescence 14/10-14 (Russia), and Ana *2/Oc 14//2*Br 35/3/Oc 9015#87 (CIMMYT). Three varieties exceeded the standard for protein content: Ilimenskaya 2 (Russia), Lutescens 128-15 (Russia), and Lutescens 234/11 (Kazakhstan). Based on the level of sedimentation sediment, two samples were above the standard: Ilimenskaya 2 (Russia) and Lutescens 128-15 (Russia). By protein content and sedimentation level, two samples are distinguished: Akmola 2 (Kazakhstan) and Lutescence 234/11 (Kazakhstan). According to the complex of economically valuable characters, three varieties are highlighted: Weebill 1 (Mexico), CATBIRD (Mexico), and Scarlet (USA). The distinguished samples of spring soft wheat are recommended to breeders as sources of resistance to rust diseases in the creation of new competitive varieties adapted to northern Kazakhstan. At present, varieties Weebill 1 (Mexico), CATBIRD (Mexico), and Scarlet (USA) are used as parental forms in the creation of initial material with high yield, grain quality, and resistance to biotic environmental factors.