Effectiveness of known wheat resistance genes Triticum aestivum L. to Puccinia triticina Eriks. leaf rust of wheat in 2019–2020

The wheat leaf rust is widespread throughout Ukraine, which makes it necessary to monitor the effectiveness of host plant resistance genes. In 2019–2020, under conditions subpopulation pathogen, typical for Right Bank Forest-Steppe zone known genes was determined. Evaluation conducted after 2018 epiphytotypic series on a nearly isogenic Thatcher lines and cultivars that expand core gene set. According research results, they are distributed into several groups according level expression: 1) capable determining very high all local races pathogen (score 9 – no signs disease; score 8 single necrotic spots) Lr9, Lr18, Lr19, Lr21, Lr25, Lr27+31, Lr28, Lr35, Lr41, Lr43+24, Lr50, LrTm; 2) plants slightly affected by spots urediniopustules with an intensity up 5 %; 7 10 6 small medium 15 %) Lr22a, Lr32, Lr34, Lr42, Lr43, Lr46; 3) whose expression defined as labile (heterogeneous) Lr2a, Lr2b, Lr12, Lr14a, Lr14b, Lr20, Lr23, Lr24, Lr39, Lr40. last group characterized variability depends infectious load virulence population whole. We recommend using listed in selection process, taking account characteristics group. Lr1, Lr2c, Lr3, Lr3ka, Lr3bg, Lr10, Lr11, Lr13, Lr15, Lr16, Lr17, Lr26, Lr29, Lr30, Lr33, Lr37, LrB ineffective against Forest Steppe Ukraine. If associated useful traits, their use should be carried out at expense pyramiding other more effective