Object: ways of determination and expression factors of spring barley resistance to diseases and pests, its genetic traits, relation to essential economic characteristics, usage of selected valuable samples in the crop selection. Aim: determination of selective and genetic traits of spring barley resistance to the range of biotic factors and, on this basis, determination of sources of resistance to the agents of netted helminthosporium leaf blotch, helminthosporium root rots and oscinella among the selective material by means of different estimation methods, as well as determination of donor characteristics of parental forms. Methods: general scientific (methods of dialectic analysis and synthesis of the experiment, hypothesis and forecasting methods) and special methods: field, laboratory, genetic and statistical - dispersion, variance, genetic, correlation analyses. Novelty: an important scientific task on determination of selective value of spring barley modern varieties and lines according to resistance to the range of hazardous organisms has been solved. The research differs from the previous ones by determination of resistant to diseases and pests agents' samples on the basis of developed estimation method, and their usage in the crop selection. For the first time, it was determined the spring barley samples' resistance to hazardous organisms by means of autumn sowing in conditions of the field, as well as selected sources with individual and group resistance to helminthosporium diseases, high immunological properties of which were confirmed by laboratory evaluation at maximum infection load. Results: the ways of spring barley samples' immunological evaluation in conditions of the field were improved, a level of material resistance and tolerance to diseases and pests was determined, ecological and biotical plasticity according to the norm of reaction to the cultivation conditions and influence of the range of hazardous organisms was defined, genetic traits of resistance inheritance were detected. Stage of application: it has been developed a new way of spring barley resistance to helminthosporiosis agents (invention patent No. 101720 dated April 25, 2013), which allowed to determine samples that combine resistance to diseases and range of valuable economic characteristics. Determined according to the resistance to roots and leaves helminthosporiosis agents the varieties Vyklyk, Inclusive and Parnas, that are implemented into the selective process of the Crop Research Institute named after V. Ia. Iurev of the National Academy of Agricultural Sciences, were passed to the National Centre for Plant Genetic Resources of Ukraine. On the basis of usage of the developed way of immunological evaluation in partnership with the applicant the varieties Maliuvnychy, Kozyr and Vitrazh, characterized by resistance to the main hazardous organisms and high rates of valuable economic characteristics, were created and passed to the State Variety Testing. Area of application: selective determinations.
