Assessment of morphological features and antioxidant activity of radish (Raphanus sativus) in conditions of soil pollution by heavy metals and petroleum products

In phytotesting polluted soils, the indicators of plant growth and development serve as an integral assessment. At the same time, biochemical markers are of particular interest, among which products of oxidative stress and antioxidant substances are of particular importance. The article evaluates the morphological changes and antioxidant activity of a plant organism using the example of a test culture of radish (Raphanus sativus) in conditions of soil contamination with heavy metals and petroleum products. Five series of experiments were conducted using the seedling method according to the following scheme: 1) control - soil; 2) experimental samples: the soil with the addition of acetate salts of copper (in doses from 27.5 to 110 mg/kg), zinc (11.5-46 mg/kg), lead (15-60 mg/kg), cadmium (0.25-1 mg/kg), as well as petroleum products (100-1000 mg/kg). The laboratory germination of seeds, growth and development indicators of radish seeds under the influence of heavy metals and petroleum products were studied. The addition of zinc (in doses from 12.5 to 46 mg/kg) and lead (in doses from 15 to 60 mg/kg) contributed to an increase in laboratory germination of radish seeds. Copper had no significant effect on the initial growth and development of radishes. Cadmium and petroleum products in the studied doses reduce the laboratory germination of radish seeds. The effect of ecotoxicants on the content of photosynthetic pigment components, the amount of phenolic and flavonoid compounds was revealed. The content of lipid peroxidation products (diene conjugates and Schiff bases) in plants under conditions of soil contamination with Cd, Pb, Zn, Cu and petroleum products was estimated. The state of antioxidant activity in plants in response to stress caused by additional intake of ecotoxicants into the soil was determined. The level of pro-oxidant and antioxidant processes in the plant body depends on the dose and chemical properties of the introduced heavy metals and petroleum products.