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Background. There is very poorly information about the adaptive potential and resistance of plant species or their ecological groups to heavy metals (HMs). The available criteria for assessing the condition of plants and their populations in technogenic territories are laborious or insufficiently objective. Therefore, the aim of the research was to develop a plant adaptation index that allows assessing the degree of resistance of individual species, populations, and ecological groups of plants to HMs based on the integral response of physiological and biochemical parameters of the organism to a dose of the metal. Materials and methods. Seeds of ruderal species from biotopes with different degrees of HMs contamination and seeds of cultivated plants were germinated under controlled conditions on water (control) or on media containing from 1 to 10,000 μM of Cu2+, Ni2+, Zn2+ or Pb2+ ions. After 7 and 14 days of the experiment, we measured adaptive parameters: seed germination, length of axial organs, leaf area, fresh and dry mass and water content in plant organs, cell viability, electrolyte leakage from cells, intensity of LPO and superoxide anion generation, concentration of total peroxides and carotenoids, APO, catalase and SOD activities. Experiments and analyses were carried out in at least three times. The relationship between the values of the studied indices and the concentration of HMs in the medium was evaluated according to the table of critical values of Pearson correlation coefficients (r) calculated in MS Excel. Results and conclusions. Compared to the available tests, the adaptation index (AIHM) reflects more objectively the resistance of plants to HMs. AIHM can be calculated as the geometric mean of the studied adaptation effects (AE, % to water control). AE can be determined by any plant parameters (6 ≤ n ≤ 8) sensitive to HMs. In perspective, AIHM can be used to determine the degree of plants adaptation to other toxic pollutants in the environment. |
