Stem rust in recent years has acquired an epiphytotic character, causing significant economic damage for wheat production in some parts of Western Siberia. On the basis of a race composition study of the stem rust populations collected in 2016-2017 in Omsk region and Altai Krai, 13 pathotypes in Omsk population and 10 in Altai population were identified. The race differentiation of stem rust using a tester set of 20 North American Sr genes differentiator lines was carried out. The genes of stem rust pathotypes of the Omsk population are avirulent only to the resistance gene Sr31, Altai isolates are avirulent not only to Sr31, but also to Sr24, and Sr30. A low frequency of virulence (10-25 %) of the Omsk population pathotypes was found for Sr11, Sr24, Sr30, and for Altai population -Sr7b, Sr9b, Sr11, SrTmp, which are ineffective in Omsk region. Field evaluations of resistance to stem rust were made in 2016-2018 in Omsk region in the varieties and spring wheat lines from three different sources. The first set included 58 lines and spring bread wheat varieties with identified Sr genes -the so-called trap nursery (ISRTN -International Stem Rust Trap Nursery). The second set included spring wheat lines from the Arsenal collection, that were previously selected according to a complex of economically valuable traits, with genes for resistance to stem rust, including genes introgressed into the common wheat genome from wild cereal species. The third set included spring bread wheat varieties created in the Omsk State Agrarian University within the framework of a shuttle breeding program, with a synthetic wheat with the Ae. tauschii genome in their pedigrees. It was established that the resistance genes Sr31, Sr40, Sr2 complex are effective against stem rust in the conditions of Western Siberia. The following sources with effective Sr genes were selected: (Benno)/6*Lutescens 87-13 (Sr23, Sr31, Sr36). These sources are recommended for inclusion in the breeding process for developing stem rust resistant varieties in the region.Аннотация. Стеблевая ржавчина пшеницы в последние годы приобрела эпифитотийный характер, нанося значительный экономический ущерб производству зерна пшеницы в отдельных областях Западной Сибири. По результатам изучения расового состава популяций стеблевой ржавчины, собранной в 2016-2017 гг.132 Вавиловский журнал генетики и селекции / Vavilov Journal of Genetics and Breeding • 2020 • 24 • 2 Stem rust in Western Siberiarace composition and effective resistance genes в Омской области и Алтайском крае, выявлено 13 патотипов в омской популяции и 10 -в алтайской. Дифференцирование рас стеблевой ржавчины проводили с помощью тестерного набора 20 североамериканских линий-дифференциаторов Sr генов. Гены патотипов стеблевой ржавчины омской популяции авирулентны только к гену устойчивости Sr31, алтайские изоляты авирулентны, помимо Sr31, к генам Sr24, Sr30. Низкая частота вирулентности (10-25 %) патотипов омской популяции установлена для Sr11, Sr24, Sr30, а патотипов алтайской -для Sr7b, Sr9b, Sr11, SrTmp, которые ...

Hexaploid triticale ( × Triticosecale Wittmack) lines were examined using molecular markers and the hybridization in situ technique. Triticale lines were generated based on wheat varieties differing by the Vrn gene systems and the earing times. Molecular analysis was performed using Xgwm and Xrms microsatellite markers with the known chromosomal localization in the common wheat Triticum aestivum , and rye Secale cereale genomes. Comparative molecular analysis of triticale lines and their parental forms showed that all lines contained A and B genomes of common wheat and also rye homoeologous chromosomes. In the three lines the presence of D genome markers, mapped to the chromosomes 2D and 7D, was demonstrated. This was probably the consequence of the translocations of homoeologous chromosomes from wheat genomes, which took part during the process of triticale formation. The data obtained by use of genomic in situ hybridization supported the data of molecular genetic analysis. In none of the lines wheat-rye translocations or recombinations were observed. These findings suggest that the change of the period between the seedling appearance and earing time in triticale lines compared to the initial wheat lines, resulted from the inhibitory effect of rye genome on wheat vernalization genes. PLANT GENETICS

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