945 ISSN 1022-7954, Russian Journal of Genetics, 2019, Vol. 55, No. 8, pp. 945–954. © Pleiades Publishing, Inc., 2019. Russian Text © The Author(s), 2019, published in Genetika, 2019, Vol. 55, No. 8, pp. 893–903. Analysis of Spring Triticale Collection for Leaf Rust Resistance Genes with PCR Markers P. Yu. Kroupin a, b, *, I. V. Gruzdev a , M. G. Divashuk a, b , M. S. Bazhenov a, b , A. A. Kocheshkova b , A. G. Chernook a, b , M. V. Dudnikov a , G. I. Karlov a, b , and A. A. Soloviev a, c a All-Russia Research Institute of Agricultural Biotechnology, Moscow, 127550 Russia b Centre for Molecular Biotechnology, Russian State Agrarian University, Moscow, 127550 Russia c Tsitsin Main Botanical Garden of the Russian Academy of Sciences, Moscow, 127276 Russia *e-mail: pavel-krupin@yandex.ru Received December 10, 2018; revised March 10, 2019; accepted March 19, 2019 Abstract—The results of PCR analysis of the collection of spring triticale accessions for the presence of genes Lr9, Lr12, Lr19, Lr24, Lr25, Lr28, Lr29, and Lr47 (conferring resistance to wheat leaf (brown) rust caused by Puccinia triticina Erikss.) with the use of molecular markers and isogenic lines carrying target genes (as a positive control) are presented in this article. The absence of positive PCR amplification of the DNA markers for the Lr9, Lr24, Lr28, Lr29, and Lr47 genes is observed in all the studied accessions of the spring triticale collection. The accessions Lena 1270, 25AD20, k-1763, k-3256, and Arta 59 are found to carry the Xgwm251 marker allele of the same size as that of isogenic Thatcher line with Lr25. PCR analysis using the LrAg marker shows that such triticale accessions as Pamyati Merezhko, Ulyana, V20-140, S17, PRAG 554/1, C95, 08871, RIL-130 R22-2, 172-1-16, C250, 08857, 09228, 131/17, A2-16-11, POPW9, PRAG 500, C260, Arta116/2, PRAG 554, AVS19883, k-1220, PRAG 553/1, C254, PRAG 518, PRAG 418, R-7-5 RIL202, L2413, and L8-6 carry a fragment close in size to that of the isogenic Thatcher line with Lr19 (used as positive control). Thus, we have shown that the gene pool of spring triticale is extremely depleted in leaf rust resistance genes. Active work is required on the introgression of new resistance genes both from the known donor lines of triticale and from bread wheat. Keywords: triticale, leaf rust, Lr genes, PCR markers, resistance DOI: 10.1134/S1022795419080088 INTRODUCTION Triticale is a man-made grain crop produced by crossing wheat with rye in order to merge the best traits of parent species into a single plant. New variet- ies are transferring this crop from a promising category to one of the top demanded cereals. In 2016, global triticale acreage covered 4.16 million hectares, and world grain production reached 15.2 million metric tons [1]. Triticale world production has steadily increased during the past 20 years with a 50% increase in the last decade. Triticale is mainly grown in Poland, Germany, France, Belarus, and Russia as feed grain and forage crop [2]. At the beginning of the commercial cultivation of triticale, diseases did not significantly reduce its yield. However, with the expansion of the area of triticale planting along with the widespread use of the cultivars with a limited diversity of resistance genes, an intense selection started occurring in the pathogen population in favor of rare or mutant virulent alleles. This leads to the emergence of pathogen virulent races and over- coming of plant resistance. One of the most common diseases of triticale is wheat leaf rust caused by the pathogen Puccinia triticina Erikss. [3]. Under field conditions, the same pathogen population parasitizes both crop plants [4]. Leaf rust is one of the most serious wheat diseases, which may cause up to 50% yield losses [5]. Crop pro- tection with fungicides increases the cost of the end product and the load on the environment. Moreover, it is effective only when timely applied. An alternative approach would be the development of cultivars with genetic resistance to crop diseases. Being an allopolyploid, triticale combines the leaf rust resistance genes of both wheat and rye and, there- fore, possesses a large variety of response and protec- tive reactions. To date, a total of 75 leaf rust resistance genes have been already identified [6], including the Lr25, Lr26, and Lr45 genes, which were introgressed into wheat from the rye genome [7]. By now, many of the Lr genes have already lost their efficacy [8, 9]. Therefore, in addition to the gene pool of wheat and rye, the genes of closely related species (such as Triti- PLANT GENETICS