Background. Stem rust of wheat, caused by the biotrophic fungus Puccinia graminis Pers. f. sp. tritici Eriks. et Henn., is a dangerous disease that afflicts serious economic damage to the cultivation of durum wheat.Materials and methods. Cultivars and promising materials developed at the Spring Durum Wheat Breeding Laboratory, Omsk Agrarian Scientific Center (OASC), lines obtained under the CIMMYT and KASIB programs, and accessions from the VIR collection were the objects of research. Field experiments, phenological observations, and assessment of stem rust resistance were carried out from 1990 through 2019 in the OASC experimental fields using conventional methods. Resistance to the Ug99 race was evaluated under natural infection pressure at the Kenya Agricultural and Livestock Research Organization (KALRO).Results. Promising source material was identified and included in the Laboratory’s breeding program. The ways were shown to develop stable cultivars of spring durum wheat for the environments of Western Siberia. A strategy was proposed for the selection of genotypes in hybrid combinations of spring durum wheat: it would include early selection (starting from F2 ) for disease resistance with simultaneous screening for quantitative traits and pasta-making qualities. The description and advantages of cv. ‘Omsky korall’, submitted to the State Variety Trials in 2018, are presented. This cultivar combines high yield, adaptability, resistance to the local population and the Ug99 race of the stem rust pathogen, and excellent pasta-making qualities.Conclusion. As a result of these studies under heavy stem rust pressure in Western Siberia, all breeding nurseries obtained source material resistant to the Omsk population of P. graminis. The released cultivars ‘Omskaya yantarnaya’ and ‘Omsky izumrud’ demonstrate resistance to the Omsk population of the stem rust causative agent.

There have been presented study results of the spring durum wheat varieties grown in the southern forest-steppe area of the Omsk region on kernel hardness. The objects of research were the varieties of ecological variety testing conducted by various Russian and Ukrainian scientific institutions. The study was conducted in the period from 2003–2015. Experimental plots of 10 m2 were placed in 4 sequences. The varieties were sown in weedfree fallow. The soil of the experimental plot was weakly leached blackearth (chernozem), medium humus (6.2%), and loamy. The sowing date is 14–15 of May, the sowing rate is 4.5 million of germinated kernels per ha. The average hardness index in 2003–2015 was 70.1%. The varieties varied from 66.0 (the variety “Svetlana”) to 74.6% (the variety “Saratovskaya zolotistaya”). The differences between maximum and minimum were 8.6%. The variation through the years was from 51% to 92%, from 21% (the varieties “Angel”, “Omsky korund”) to 34% (the variety “Saratovskaya zolotistaya”). The calculated coefficient of variation showed that the variability degree ranged from little to medium. Coefficients of variation varied from 9.3% (the variety “Angel”) to 14.3% (the variety “Bezenchukskaya 182”). According to S. A. Eberhart, W. A. Russel the stability index indicates a lower variability of the varieties “Angel”, “Omsky korund”, “Altayskaya niva”, “Nik”, “Kharkovskaya 23”, “Tavolga”. The value of the regression coefficient (bi) for kernel hardness ranged from 0.77 to 1.23. The varieties “Voronezhskaya 9”, “Elizavetinskaya”, “Altayskaya niva”, “Omskaya stepnaya” and “Bezenchukskaya stepnaya” turned to be most responsive to the conditions (according to the Eberhart – Russell test). The varieties “Angel”, “Aleyskaya”, “Zarnitsa Altaya” had a weak reaction to the environmental conditions. There has been identified phenotypic correlation between the trait and productivity, 1000-kernel weight, nature weight, gluten quality, pasta color. The correlation between these traits is positive, on average r = 0.30–0.440.

Field research was carried out in 2018-2019 on the premises of Omsk Agrarian Research Centre, exactly the breeding crop rotation of the laboratory of durum wheat breeding as well as at the reference point of seed production in the steppe zone in the village of Novouralsky Tavrichesky district of Omsk region. The experiments were conducted in a complete fallow. The area of the plots was 10 m², repeated four times, the location was random. Weather conditions during the vegetation period of 2018 were contrasting both in terms of precipitation and temperature. Grain formation took place in late August - early September, which had a significant impact on grain quality. In 2019, atypical meteorological conditions were observed: favorable in the first vegetation period and arid - in the second (Volga type of drought). The productivity of durum wheat lines was estimated in terms of adaptive capacity and stability. Scientific data on the parameters of grain quality and disease resistance are highlighted. Yields of durum wheat lines varied considerably depending on agro-climatic conditions of the year and cultivation background. The best conditions for the growth and development of genotypes were set up in the southern forest-steppe zone of Omsk, the maximum crop yield was observed in the Gord. line 08-67-1, Gord. 09-68-1, Gord. 05-12-7(v), Gord. 08-107-5. The general adaptive ability is close to zero, that shows stability of genotypes in external environment. Specific adaptive ability revealed in the lines: Gord. 10-33-3, Gord. 10-8-4, Gord. 11- 70-7, Gord. 11-77-8, Gord. 11-99-1. The authors highlight the following promising lines according to the experimental results: Gord. 05-12-7(v), Gord. 08-107-5, Gord. 09-68-1, Gord. 08-67-1. Selection assessment of promising lines was carried out on the indicators of grain quality and disease resistance. The following parameters are seen as good quality indicators at the Gord line 11-70-7: weight of 1000 grains is 49.75 g and high resistance to stem rust (6%). According to the quality of grain and weight of 1000 grains, Gord. line 09-68-1 is better than Zhemchuzhina Sibiri, affection of brown and stem rust is minimal that is interesting for selection procedures. The following varieties are valuable from the point of view of breeding, stability of genotype, high productivity, quality of grain and pasta and resistance to disease: Gord. 05-12-7(v), Gord. 08-107-5, Gord. 09-68-1, Gord. 08-67-1, Gord. 11-70-7, Gord. 11-99-1.