Dmytrenko Y. Breeding and Genetic Value Sources of Resistance to Leaf Rust Pathogen of Winter Wheat

The thesis is devoted to investigation of breeding value of genetic resources, varieties, hybrid combinations of bread winter wheat on the basis of resistance to leaf rust pathogen on natural and artificial infectious backgrounds in order to search for new effective sources of traits, identifying their donor properties, studying mechanisms of genetic control and inheritance of this trait, creation of lines with signs of resistance to a group of leaf diseases and a complex of valuable economic signs their introduction into breeding programs. In dissertation the mechanisms of genetic control and inheritance of resistance to the causative agent of leaf rust in six collection samples of bread winter wheat: Тх91v4511, Тх92v4511, НВЕ 0140-119, НВЕ 0303-156, НВЕ 208-120, НВЕ 0425-156 were investigated. According to hybridological analysis results (phenotypes split into «resistant/susceptible» to leaf rust), F2 found: monogenic control traits in samples HBE 0303-156 and HBE 0425-156 – one dominant resistance gene, corresponding to 3:1 cleavage; Tx92 v 4511 – one recessive gene (1:3); digenic control traits in HBE 0140-119 and HBE 208-120 samples – one recessive and one dominant genes (13:3); Tx91 v 4511 – two duplicate recessive resistance genes (7:9). Discovered genes are independent to known effective ones. Created lines of bread winter wheat were used in plant breeding investigations in the Laboratory of winter wheat breeding of Breeding of Cereal Crops Department of the V. M. Remeslo Myronivka Institute of Wheat of the National Academy of Agrarian Sciences of Ukraine, Department of Breeding and Seed Production of Cereal Crops of the National Scientific Center «Institute of Agriculture of NAAS» and was gave to the National Centre for Plant Genetic Resources of Ukraine.