Screening of winter soft wheat varieties of Russian and foreign breeding for resistance to brown rust in the conditions of the foothill zone of the Central Caucasus

Abstract

The article describes the stages of immunology testing for the development of winter soft wheat varieties. It also discusses the issues of leaf rust resistance, the population structure of Puccinia tritici f. sp. tritici Eriks., the methods of evaluation and selection of stock material for selective breeding with multiple resistance genes and showing high genetic diversity. 25 samples of winter soft wheat (Triticum aestivum L) obtained from the N.I. Vavilov’s (VIR) plant genetic resources gene bank and 47 Thatcher isogenic lines with the following genes were used as test articles. The study showed that the following genes could be considered effective for the resistance to a local population of leaf rust: Lr9, Lr19, Lr24, Lr25, Lr30, Lr32, Lr34, Lr36, Lr41, Lr42, Lr45, Lr47, Lr51, Lr53, Lr67.The analysis of phenotypic traits allowed identifying 6 phenotypic groups: MHTT, PGTT, RHTT, NHKP, ТQТР, QHKP. The T-group phenotype that is virulent toLr9, Lr16 and has an incidence rate of 40.0% is typical for all grain producing regions in Russia and worldwide. They are predominant in the studied population of P. triticinа. The incidence rates of RHTT, QHKP, MHTT phenotypes that are avirulent to Lr9, Lr24 genes are 13.3, 3.3 and 10.0%, respectively. The incidence rate of PGTT and NHKP phenotypes that are avirulent to, Lr9, Lr24 Lr26, Lr2а, Lr3 genes is 33.3%. The intrapopulation genetic variation estimated using the Shannon–Weaver diversity index is high (H=2.51).The screening allowed identifying leaf rust resistant winter soft wheat varieties ranked as follows: resistant – 11, intermediate – 9, susceptible – 5 samples. It was proposed to use winter soft wheat varieties of foreign breeding from the Collection of Worldwide Crop Genetic Resources (Vavilov All-Russian Scientific Research Institute of Plant Industry (VIR)), such as Dorota (France), Genoveva (Slovakia), Arial (Ukraine), Elton (USA), Verita (Slovakia), Muza (Poland), Alauda (Germany), Fenezja (Poland), Vatazbok (Ukraine), and Russian varieties of Prima and Omskaya 5.