Long-Term Multilocal Monitoring of Leaf Rust Resistance in the Spring Bread Wheat Genetic Resources from Institute of Plant Genetic Resources (VIR)

Abstract

Triticum aestivum L. (bread wheat) is the most important cereal crop in world grain production, including in the territory of the Russian Federation. One of the most important factors influencing the yield and quality of wheat grain is the affection of plants with leaf rust (Puccinia triticina Erikss.). To broaden the set of sources for effective rust resistance, spring bread wheat samples from N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) were monitored for adult resistance to the disease under natural infections for many decades at three distant locations of the Russian Federation: the Dagestan Experimental Station (DES) of VIR (10,549 accessions), Yekaterinino Experimental Station (YES) (4384 accessions), and Pushkin Experimental Field (PEF) (7704 accessions). Information on the disease development at these three stations is presented at least for 51 last years. As a result of disease development evaluation under natural epiphytotic conditions for not less than 3 years, 293 (15 landraces, 127 breeding lines, and 151 commercial varieties), 118 (1 landrace, 38 breeding lines, and 79 commercial varieties), and 127 (10 landraces, 48 breeding lines, and 69 commercial varieties) samples were classified as resistant to leaf rust at DES, YES, and PEF, respectively. Among samples from the State Register of Breeding Achievements in Russia, 15, 13, and 8 spring wheat varieties were resistant to leaf rust at DES, YES, and PEF, respectively. Juvenile resistance was estimated under laboratory conditions after seedling inoculation with a complex population of P. triticina: 73 highly resistant varieties and breeding lines were identified; all landraces, including those classified as resistant in the fields, were susceptible to disease at the seedling stage. A total of 26 wheat accessions were identified to be resistant to leaf rust at two to three locations; 14 of them possess adult resistance, and 12 samples have seedling resistance. According to results of PCR amplification with primers specific to markers of effective genes for leaf rust resistance, 6 accessions have gene Lr9, 1 sample is protected by Lr19, and 1 sample possesses gene Lr24. Wheat samples identified as possessing effective seedling or adult resistance could be of interest for breeding in some regions of the Russian Federation and other countries.