[Genetic characterization of rye samples with regard to leaf rust resistance]

The genetic control of leaf rust resistance has been investigated by test crosses and the test-clone method in the rye samples Malysh 72-2, Chulpan 3, Immunnaya 4, Yaroslavna 3, Lovashpatonae 2, Gotor 2, Talovskaya 12-2, Braunrostresisten 2, Orlovskaya 9-2, 3098/18, and 4001/10. It has been found that this trait is controlled by a set of nonidentical oligogenes. Dominant gene Lr6 controls leaf rust resistance in Chulpan 3 and Immunnaya 4; Lr5, in Malysh 72-2; and Lr-c, in Yaroslavna 3. Test crosses have shown that genes Lr-a and Lr-b differ from the genes determining the resistance in Gotor 2 and Braunrostresisten 2. In German samples 3098/18 and 4001/10, the resistance to the Petersburg population of the pathogen is controlled by nonallelic genes Lr-a and Lr-b. It has been found that gene Lr-b is not identical to the resistance gene of Lovashpatonae 2, and Lr-a is not identical to Lr-c. In all samples, resistance to the leaf rust population is controlled by dominant genes from the stage of seedlings till maturity. Highly efficient Lr genes are present in the samples Malysh 72-2, Chulpan 3, Immunnaya 4, Yaroslavna 3, Lovashpatonae 2, Gotor 2, Talovskaya 12-2, 3098/18, and 4001/10. In addition to the oligogenes, most samples possess genes efficiently controlling particular clones of the pathogen.