IDENTIFICATION OF LEAF RUST RESISTANCE GENES IN SPRING SOFT WHEAT SAMPLES DEVELOPED IN RUSSIA AND KAZAKHSTAN

Abstract

Leaf rust caused by Puccinia triticina Erikss. is a harmful disease of spring soft wheat in Russia and Kazakhstan. For higher effectiveness of selection programs, Kazakhstan-Siberian Network for Wheat Improvement (KASIB) including the leading institutions of Kazakhstan and Siberia was established. Integrated ecological studies of selection material including those on leaf rust resistance are conducted under the KASIB programs. The work goal is to identify leaf rust resistance genes using the plant pathology and molecular approaches. Forty seven samples of spring soft wheat are included in KASIB program for 2019–2020. Virulence-labeled clones and geographically distant populations of P. triticina were used for plant pathology testing in seedling phase, and 11 wheat samples with high level of rust resistance at seedling phase were found. Identification of target 21 Lr-genes has been performed using molecular markers with positive result in 82 % of the studied samples. Wheat samples highly resistant in the seedling phase demonstrated Lr24-gene alone or in combination with partially effective genes Lr26 and Lr9, as well as genes LrSp and Lr6Agi1, not identical to the known effective genes; as well as effective combinations of genes: Lr19+Lr26; Lr9+Lr26 and Lr19+Lr26+Lr41. The resistance genes Lr34 and Lr37 of adult plants have been detected in 8 % of the lines. In samples susceptible at seedling phase, low efficacy genes Lr1, Lr3, Lr10 are frequent. The screening has demonstrated high Lr-genes diversity of the spring wheat collection and considerable progress in wheat selection for the leaf rust resistance in Russia and Kazakhstan.