Kyrylenko V. Methods of creating the source material of winter wheat resistant to unfavorable environmental factors of Forest-Steppe of Ukraine

Object of study: patterns of recombination and mutation processes, pecuilarities of variability and inheritance of agronomic traits; formation and expression of resistance to unfavorable environmental factors in winter bread wheat breeding. The purpose: to substantiate theoretically, to develop and to improve methodical approaches to the assessment and selection of sources to create original material and bread winter wheat varieties in the Forest-Steppe of Ukraine. Methods: field, laboratory, and statistical. Results: high-yielding winter wheat varieties have been created in collaboration, nine ones are included in the State register of plant varieties of Ukraine, during 2008-2015 their acreage exceeded 120,000 ha. Six varieties have been submitted to the State Variety Testing of Ukraine. Varieties and lines being sources of adaptive features were identified; new source material has been created to be used in practical breeding at the MIW and another breeding institutions. Methods for the assessment of frost-, drought-, heat tolerance and resistance to major pathogens have been adopted in breeding process. Novelty: for the conditions of Forest-Steppe of Ukraine the tendency of change of weather conditions and duration of the interphase periods of the cropping season of plants has been established; integrated diagnostics determining frost and winter hardiness, drought and heat tolerance, and resistance to major pathogens have been improved with subsequent selection of new genotypes on artificial backgrounds; individual approach to accelerated creation of varieties with complex resistance against major diseases of wheat has been developed; efficiency in selection of winter wheat genotypes when using crosses with spring wheat was proved, the extension of forming process in spectrum and proportion of mutations and peculiarities of expression of transgressions for elements of spike productivity in F3М2-F5М4 resulted from actions of mutagens on F1 seeds was revealed; the possibility was proved to identify and select genotypes combining productivity and resistance to pathogens. The program was substantiated for the creation of new lines with high yield potential and resistance to action of extremal environmental factors. Fielf of use: agriculture.