Korsak V. Breeding assessment of the gene pool of tobacco for creation of the initial disease-resistant material

3. The technique of assessment of breeding material of tobacco for group resistance to disease-producing factor is improved and applied. First the assessment is carried out and the best samples of the collection of different ecological and geographical origin with resistance to Licopersicum virus 5, Tobacco ringspot nepovirus and Tomato spotted wilt virus are found that allowed to characterize the initial material for adaptive features in combination with resistance to disease-producing factor. First consistent patterns of inheritance of group resistance to disease-producing factor in hybrids with various manifestations of resistance of parental forms are determined are specified and the analysis of inheritance of the main quantitative signs in hybrids is carried out. The selection material of tobacco is created and the best sort samples with a combination in one genotype of group resistance to disease-producing factor and valuable signs of efficiency are selected. The technique of selection process on creation of resistance varieties is improved. Experimental studies allowed to trace 45 varieties, which are characterized by group resistance to diseases in combination with economic-value indicators and serve as the basic collection of tobacco. On their basis the collection of samples with group resistance to disease-producing factor is created which is used in breeding work. The best samples were submitted to the National Center for Plant Genetic Resources of Ukraine. New grades Berley 22 and Berley 88 are created and prepared for studying on new varieties sby tate strain testing. Selected attribute collection with group resistance to diseases and groups with resistance to Licopersicum virus 5, Tobacco ringspot nepovirus, Tomato spotted wilt virus and Potato virus Y are created. By results of improvement of methodical approach to the assessment of selection material of tobacco resistance to Licopersicum virus 5, Tobacco ringspot nepovirus and Tomato spotted wilt virus methodical instructions and recommendations about cultivation of tobacco of new grades are published. Keywords: tobacco, collection, selection, resistance to diseases, inheritance of signs, efficiency.