Sideral cultivar as donor of increased cold resistance in oilseed flax breeding

Aim. To create valuable breeding material of oilseed flax with increased cold resistance via hybridization with germplasm of the Sideral variety. Results and Discussion. Cold resistance of the investigated oilseed flax genotypes was evaluated by cold seed germination on filter paper. The hybridization method and experiment design were routine in flax breeding in accordance with the recommendations. The field experiments were conducted in the experimental fields of the Institute of Oilseed Crops of the National Academy of Agrarian Sciences in 2017-2021. Crossings were carried out according to the following scheme: stable×stable, stable×moderately stable, stable×unstable, backcrossing, triple and stepwise crossings involving four and five components. Genotypes of different geographical origins were studied: French (Sideral), Ukrainian (Aisberh, A-11, B-11, Vodohrai) and Canadian (K-8085, Saskatoon). The data were statistically processed. The French variety, Sideral, with high resistance to hypothermic stress was chosen as a donor of cold resistance. It was found that simple paired crossings using a more resistant component as a parent gave a significant boost in the cold resistance of the obtained material. The most effective methods were stepwise crosses involving three to five highly resistant parents and backcrossing with a more resistant component. Twenty-eight 28 hybrid combinations have been obtained; they are currently being tested in nurseries of splitting families, where elite plants are selected by economic value. Conclusions. By using germplasm of the Sideral variety, valuable material was obtained for further genetic studies and breeding to develop oilseed flax varieties with increased resistance to hypothermic stress.