Aim. Improving methods for increasing the efficiency of obtaining callus cultures and somaclones flax (Linum usitatissimum L.) in vitro. Methods. Hypocotyl segments were cultured on Murashige Skoog nutrient medium supplemented with sucrose (30 g/l) phytohormones at various concentrations. Other conditions: photoperiod 16 hours, illuminance 2500 lx, relative humidity 60–80%, air temperature 22–2...