UDK 633.11:631.527:632.4:577.2 INVESTIGATION OF INTERMEDIARY WHEAT-AGROPYRON HYBRIDS ON RESISTANCE TO LEAF RUST 1 Center of Molecular Biotechnology, Russian State Agratian University – Moscow Timiryazev Agricultural Academy, Moscow 127550, Russia P.Yu. <...> Krupin1, M.G. Divashuk1, V.I. Belov2, A.I. Zhemchuzhina3, E.D. Kovalenko3, V.P. Upelniek2, 4, G.I. Karlov1 e-mail: pavelkroupin@gmail.com, divashuk@gmail.com, karlov@timacad.ru 2 Tsitsin Main Botanical Garden, RAAS, Moscow 127276, Russia e-mail: nex_snegiri@mail.ru 3 All-Russia Research and Development Institute of Phytopathology, RAAS, Bolshye Viazemy settlement 143050, Odintsovo district, Moscow province, Russia e-mail: zhemchuzhina@vniif.ru, kovalenko@vniif.ru 4 Vavilov Institute of General Genetics, RAS, Moscow 119991, Russia e-mail: vla-upelniek@yandex.ru Received August 19, 2012 S u m m a r y The estimation was made for 18 variants of octaploid winter wheat-Аgropyron hybrids (WAH) (2n = 56) on juvenile resistance to 10 isolates of leaf rust. <...> By the use of molecular markers the presence of different subgenomes of Thinopyrum sp. in investigated variants was shown. <...> In variants of WAH the authors revealed a polymorphism on resistance to test-isolates of leaf rust, which may be due to various number of agropyron chromosomes in genome. <...> Leaf rust (Puccinia triticina Eriks.) is the cause of a significant damage to wheat (crop loss up to 50 %), especially in southern regions of Russia (1). <...> Over 50 genes for rust resistance have been detected (2), and molecular markers have been developed for many of these genes (3). <...> Very often sources of such genes are wild relatives of wheat. <...> In particular, genes Lr24, Lr29, and Lr19 of Thinopyrum ponticum (genomic constitution JJJJsJs, 2n = 70) and Lr38 gene of Th. intermedium (genomic constitution JSJs, 2n = 42) were transferred into wheat through intergeneric hybridization in order to provide its resistance to many races of the pathogen (4). <...> The emergence and spread of new races weakens the resistance caused by these genes (5-7), that’s why it is important to find new genes for complete or partial resistance to leaf rust of wheat that will help to develop <...>