SOURCES OF HORIZONTAL RESISTANCE OF FLAX TO SKEIN PATHOGEN IN THE SELECTION MATERIAL
The stage in studies of breeding material stability, varieties offlax to harmful organisms is the work on the formation, comprehensive study, maintenance and practical use of "Collection of microorganisms-pathogens offlax", which is formed on the basis of working collections in the 90 - ies. The study of cultural and morphological parameters is an integral part of the collection content. Cultural properties of isolates of skein pathogen are defined. Characteristics of two cultural types of skein pathogen biological samples (septoriosis) are given. The first type included biological samples forming concentric rings, differing in color, colonies in this case are dense, woolly. Here pycnidia are formed on the entire surface of the culture, the second type related strains, forming a sector dramatically different from the entire surface of the colony, pycnidia located in the centre of the colonies. Representatives of the first type are more common than of the second. Connection between morphological type of colonies and sporulating ability was found. Among the isolates of Septoria linicola, the largest number of spores formed isolates of the first type. Regularities in geographical distribution of strains of the first and second type and their relationship with certain flax varieties were not noted. Parameters of the size of spores and pycnidia of the pathogen are specified. The study of cultural and morphological properties will allow more targeted selection of biological samples to create a stable artificial population of the pathogen. In field conditions on artificially-provocative background to skein, in dynamics resistance to disease of breeding material of flax is defined. Among the studied 731 breeding lines of flax 11.3 ... 32.0 % occupied the line with a low rate of disease. Level of the sample horizontal stability is estimated on breeding lines with low "speed" of development of the disease. The selected genotypes with horizontal type of resistance for breeding practice: l-2685-6-7 l-2564-8-3, 013612-4-1-1, l-2421-5-11 l-2631-8-2 l-2654-8-11 etc. Lines: l-2634-6-4, l-2634-6-4, l-2686-7-2, l-2688-7-8, 0-13677-7-2 et al. are characterized by group resistance to Fusarium wilt, rust and skein. The use of the identified sources of stability with group stability in breeding programs allows to increase the efficiency of breeders and opens wide opportunities for stabilization and further growth, both productivity and quality of flax products. Valuable breeding material was transferred to the National collection of Russian flax for use in practical breeding.