ASSESSMENT OF THE RESISTANCE OF PLANTS TO TOXIC CONCENTRATIONS OF BORON AND LEAD

In the laboratory experiment, we studied the growth and development of dicotyledonous and monocotyledonous plants on the example of radish and barley, respectively, in soil containing boron at a dose of 0, 8, 80, 800, 8000 mg/kg. We evaluated the possibility of reducing boron toxicity in the soil by short-term cultivation of plants. According to the standard method for determining soil toxicity by changing the germination of seeds of higher plants at the early stages of their development (FR.1.39.2006.02264), soil with a boron concentration of 8000 mg/kg is classified as moderately toxic. Radish (dicotyledonous), in comparison with barley (monocotyledonous), at the stage of seed germination was more sensitive to the high content of boron in the soil. Inhibition of linear growth of radish and barley shoots under the action of boron at a dose of 8000 mg/kg is 44 and 69%, respectively, relative to the control and causes yellowing of the shoots. Boron at a dose of 8000 mg/kg causes a decrease in the catalase activity of the soil. At the same time, the inhibitory effect of boron cannot be eliminated by short-term cultivation of dicotyledonous and monocotyledonous plants. In a separate laboratory experiment, the effect of boron on the accumulation of lead by barley seedlings and their metabolic response when grown in soil with different doses of boron and lead was studied. The role of boron in the accumulation of lead by barley roots has not been established. In relation to shoots, a positive role of boron in reducing the toxic effect of lead in the soil by reducing its accumulation by aboveground biomass was revealed.