Assessment of the adaptive potential of spring rapeseed varieties (Brassica napus L.) in different soil and climatic zones of Ukraine

Purpose. To study the stability and plasticity of spring rapeseed varieties, in order to assess their adaptability potential in the Steppe, Forest-Steppe and Polissia zones, and also select the most ecologically plastic varieties among them. Methods. Field, laboratory, analytical and statistical. Results. Seven varieties of spring rapeseed, included in the State Register of Plant Varieties suitable for dissemination in Ukraine, were studied on indicators of plasticity and stability of yield traits, weight of 1000 seeds, protein and oil content. The highly plastic intensive varieties ‘DK 7150 CL’, ‘DK 7160 CL’ and ‘Sunder’ were selected for yield among the studied varieties, which are able to respond appropriately to changing of growing conditions. Varieties ‘DK 7150 CL’ and ‘DK 7160 CL’ belong to intensive varieties for the parameter of weight of 1000 seeds. The variety ‘Sunder’ was also highly plastic for this parameter. The varieties ‘Axana’, ‘Bilder’ and ‘CLICK CL’, according to their protein content, belong to the intensive type varieties that are capable of combining sufficiently high valu­es of the studied parameter with its stability under changing conditions. Variety ‘DK 7150 CL’, which was low-plastic, has a rather low positive value of the average group deviation of the reaction stability coefficient, therefore, it can be attributed to widely adapted genotypes. Varieties ‘DK 7160 CL’, ‘DK 7175 CL’ and ‘Sander’ belong to highly plastic intensive varieties in oil content. Varieties ‘DK 7175 CL’, ‘Builder’ and ‘CLICK CL’ are showed high stability for yield, varieties ‘Axana’, ‘Sunder’ and ‘CLICK CL’ for weight of 1000 seeds. The varie­ties ‘DK 7160 CL’, ‘DK 7175 CL’, ‘DK 7150 CL’ and ‘Sunder’ were highly stable in protein content, in oil content – varieties ‘DK 7150 CL’, ‘Axana’, ‘Builder’ and ‘CLICK CL’. Conclusions. It were established that high-intensity varieties for yield and weight of 1000 seeds in the Steppe, Forest-Steppe and Polissia zones are ‘DC 7160 CL’ and ‘DK 7150 CL’, for protein content – varieties ‘Axana’, ‘Builder’ and ‘CLICK CL’, for oil content – varieties ‘DK 7160 CL’, ‘DK 7175 CL’ and ‘Sunder’. The evaluation of the plasticity and stability of rapeseed varieties, which were included in the State register of plant varieties suitable for dissemination in Ukraine, makes it possible to select varieties that belong to the intensive type. According to the research results, varieties which are able to successfully adapt to the limiting environmental factors and stress in various soil and climatic zones have been selected.