Common wheat cultivars have been protected from stem rust for several decades worldwide by the Sr31 resistance gene transferred from Secale cereale L. (cv. Petkus). In 1998, Sr31 was overcome in Uganda by the Ug99 race of Puccinia graminis f. sp. tritici Eriks. & Henn. (Pgt). The Ug99 race and its derivatives have spread widely in Africa, neighboring regions and Europe. However, Sr31 remains effective in other areas of the world, including Russia. To breed wheat with durable resistance, it is promising to research the resistance mechanisms of nonhost species and introgressive cultivars. The aim of the research was to estimate the resistance of S. cereale and Triticum aestivum cultivars with Sr31 to stem rust and to study the mechanisms of incompatibility of Pgt with plants at the cellular level. The research was carried out in Western Siberia (Russia, Omsk region) in 2018–2022. Rye and wheat with Sr31 (cvs. Kavkaz, Seri 82, Bacanora (=Kauz’s’), NIL Thatcher TcLr26/Sr31) were resistant at the stages of seedling and adult plant, and cv. PWB343 was more susceptible to disease. Cytological studies have shown that Pgt died on the rye plants on the surface, and cv. Petkus intensively suppressed the development of the appressoria necessary to penetrate into tissues. Wheat cultivars inhibited the Pgt development mainly on the surface and while it attempted to penetrate into the stomata (pre-haustorial resistance). It has been demonstrated that Pgt has to adapt step-by-step to the surface and tissue properties for compatible interaction, which may be the reason for the durable effectiveness of Sr31.

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The extension of winter bread wheat areas in Western Siberia is accompanied by the introduction of new varieties, the adaptive properties of which require careful evaluation. The purpose of the current work was to characterize the numbers of the Competitive Variety Testing (CVT) according to the parameters of ecological adaptability and stability. The objects of research through the years of 2016–2020 were 12 winter bread wheat samples from the CVT laboratory for winter grain crop breeding of the FSBSI “Omsk Agricultural Research Center”. The highest values of the linear regression coefficient were identified in the lines ‘22/16’, ‘24/16’, the varieties ‘Yubileinaya 180’, ‘Omskaya 4’ (bi = 1.15–1.19). The varieties ‘Priirtyshskaya’, ‘Priirtyshskaya 2’, the lines ‘38/17’, ‘47/16’, ‘42/18’ (bi = 0.81–89) reacted weaker to environmental changes. The lines ‘25/16’, ‘26/16’ and ‘43/18’ (bi = 1.01–1.02) had adaptability close to a unit. The most stable productivity was identified in the line ‘24/16’ (S2 d = 0.01). The similar productivity was provided by the variety ‘Priirtyshskaya’ and the lines ‘47/16’, ‘43/18’ (S2 d = 0.05–0.10). Among the less stable varieties were ‘Omskaya 4’, ‘Priirtyshskaya 2’, the lines ‘22/16’, ‘26/16’, ‘38/17’ (S2 d = 0.30–0.48). The variety ‘Priirtyshskaya’, the lines ‘38/17’, 43/18’ (V = 22.8–23.8%) had a relatively lower productivity variability. The line ‘43/18’ (5.70 t/ha) was the best in productivity. The varieties ‘Priirtyshskaya 2’ (5.29 t/ha), ‘Yubileinaya 180’ (5.19 t/ha), the lines ‘38/17’ (5.18 t/ha), ‘47/16’ (5.01 t/ha), the variety ‘Priirtyshskaya’ (4.85 t/ha) also had a significant excess over the standard variety ‘Omskaya 4’ (4.24 t/ha). In general, the estimation of the productivity adaptability has shown that the best numbers according to this trait are characterized by different reactions to growing conditions. The most productive line ‘43/18’ is adaptable. The variety ‘Yubileynaya 180’ is of intensive type. The response to environmental changes of the varieties ‘Priirtyshskaya’, ‘Priirtyshskaya 2’, the lines ‘38/17’, ‘47/16’ was weak.

Winter rye, with all its advantages (adaptability, stress resistance, increased productivity), cannot compete with other grain crops, and the reason is grain quality to a greater extent. Solution of the issue is possible when cultivating rye varieties with a low content of water-soluble pentosans in grain. In Western Siberia, winter rye has traditionally been considered a leading grain crop, which efficiently uses environmental resources and is more productive in comparison with winter wheat and triticale. In order to increase the efficiency, the low-pentosan rye variety ‘Bereginya’ was involved in the breeding study of the Omsk Agricultural Research Center. As an initial form, this variety was used to develop a new variety ‘Irtyshskaya 2’. The purpose of the current work was to characterize this variety according to a number of valuable traits. The study was carried out on the experimental plots of the laboratory for winter crop breeding in 2020–2022. The estimation of the rye variety ‘Irtyshskaya 2’ has identified several advantages in comparison with the standard variety ‘Irina’. The new variety was more productive. Its excess over the standard variety was 0.36 t/ha (with an average productivity of 6.34 t/ha). The variety ‘Irtyshskaya 2’ is characterized by the best severity of quantitative traits (‘grain size’ and ‘head productivity’) and grain quality indicators (‘grain unit’, ‘falling number’). In order to select for increased productivity of a new variety there has been proposed grain content of a head as the main trait, which is characterized by a strong correlation with the trait ‘grain weight per head’ (r = 0.731–0.889). In 2022 the variety ‘Irtyshskaya 2’ was sent to the State Variety Testing and recommended for use in the West Siberian and East Siberian regions.