Object: changeability and stability of signs at collection samples of winterrape, induction of mutations, creation of feedstock for a selection of spring rape using method of chemical mutagenesis. Aim: selection from collection of rape source of economically valuable signs, improvement of expansion methods of genetic variety of feedstock by induced mutagenesis and inbreeding, establishment for features of inheritance of the productivity signs and create on this basis a new feedstock for the selection of varieties, adapted to the conditions of Central Forest-Steppe Zone of Ukraine. Methods: field - for establishment of co-operation features of growth and development of rape; instrumentation-gravimetric - for determination of biometrical descriptions of rape plants; statistical - for the exposure of prevailing degree, cross-correlation connections economic valuable signs, estimations of posterity from hybridization and inbreeding. Results: it was selected varieties, which had a high index of homeostasis and stability on amount of pods on central inflorescence, ? Ontario (27,0 pcs.), Bojan (29,9 pcs.); on amount of seeds in a pod - Bojan (31,3 psc.), Ontario (28,3 pcs.), Aliot (24,1 pcs.). It is well-proven that index of degree of phenotype prevailing (pp) can be used for the analysis of genetic value of F1 hybrids, that enables to educe valuable after the complex of signs combinations on the initial stages of estimation of plant-breeding material. It is set that inbreeding in F1 is accompanied by depression, at which different genotypes of winter rape there was a decline of stem height, amount of branches of the first and second orders, amount of pods on central inflorescence, lengths of pod and amount of seeds in a pod. It is set that treating of seed by solutions of mutagenes, results to appearance in М1, М2, М3 of the plants changed on morphological signs, that predefined by mutations and morphosis. Possibility of selection is well-proven in М3 of mutants after economic valuable signs: received chlorophyllous mutations (white segments are on sheets, white colouring of branches, pods and separate leafs), white colouring of chaplet of flower with the corrugated surface of petals. Novelty: Firstly in the conditions of Central Forest-Steppe Zone of Ukraine determined regularity of displaying and changeability, economic valuable signs rape varieties of different geographical origin as a feedstock for a selection. The well-proven efficiency of the use of inbreeding and induced mutagenesis in creation of new feedstock for a selection. Sphere of introduction : the standards which have a scientific and practical value got as a result of researches are included for the further use in plant-breeding-genetic work of department of genetics, selection and seed growing of Bila Tserkva National Agrarian University.
