The effect of in vitro vernalization duration on the growth and productivity of winter cereals in a phytotron-greenhouse complex

Phytotron-greenhouse complexes are widely used in breeding winter crops. Reducing the period of plant vernalization, including the use of in vitro culture will make it possible to obtain more than one generation over the year. The aim of the study was to investigate the effectiveness of in vitro vernalization of 12 wheat and triticale variety samples including facultatives, during year-round cultivation of plants in protected soil. The duration of in vitro vernalization at t +4 °C was 20, 30, 40, 50 and 60 days. The plants were set out in a hydroponic installation and grown under long-day conditions (22 hours). Only in facultative triticale could the transition to the generative growth phase occur in the variant with 20 days of in vitro vernalization: productive shoots were formed in 60 % of the ‘Valentin 90’ cultivar plants. At least 50 days of in vitro vernalization were required for most cultivars and lines, 60 days were necessary for the ‘Zubr’ (triticale) and ‘Skipetr’ (wheat) cultivars. The period from obtaining the embryo culture, vernalization, growing plants in a hydroponic installation to obtaining seed offspring lasted from 118 to 152 days for most cultivars of winter wheat and facultative triticale, and from 150 to 170 days for winter triticale. In all cultivars and lines, the total number of shoots formed on the plant significantly decreased with an increase in the duration of vernalization and the development of the capacity for productive shoot formation. The grain content of ears in the variants where the plants successfully underwent vernalization averaged 45 grains per ear for triticale and 26-40 grains per ear for wheat.