Сomprehensive assessment of barley plants regenerated from resistant to cadmium callus lines

Accumulation of cadmium (Cd) in barley grain (Hordeum vulgare L.) and its subsequent transmission through food chains to humans and animals is a serious environmental problem. The creation of stress-tolerant varieties to reduce crop losses and bioaccumulation of toxic ions can contribute to the preservation of grain quality and increase the productivity of barley on cadmium-contaminated soils. In the process of cell selection in 2017 from the original genotype of barley 8730 x Omsk in callus cultures somaclonal variants (RA) and conducted among them the selection of toxicity-resistant 15 mg/l cadmium ion lines (RACd) were obtained. Plants regenerated from callus were compared with the original genotype by physiological, biochemical and productive features, cadmium bioaccumulation in the conditions of vegetation experience. Plants were grown in normal conditions and against a provocative background of cadmium in 2017-2018. Symptoms of oxidative stress in plants were evaluated by the content of Malon dialdehyde in the leaves, the activity of superoxide dismutase, the accumulation of anthocyanins. Under stress, barley lines selected as a result of cell selection (in the medium with 15 mg/l Cd2+), differed from regenerants obtained under normal conditions( without Cd2+ ), and the initial genotype with higher antioxidant activity, chlorophyll (64 and 76%) and carotenoid (60 and 64%, respectively) content in leaves, seed productivity (1.3 and 4.5 times correspondently) and cadmium bioaccumulation in roots (5 and 100%, respectively). The obtained results indicate the feasibility of using cell engineering in breeding programs to improve the resistance of barley to cadmium toxicity.