The features of adaptation to heavy metals in different life forms and ecological groups of plants

Abstract

Background. Heavy metals (HMs) pollution causes serious disturbances at different levels of the organization of the plant world and leads to significant environmental risks. At the same time, the levels of HMs that are toxic to different species and varieties of plants vary significantly. However, there is still very little information about the features of HMs resistance in different ecological groups of plants. Therefore, the purpose of this work is to assess the degree of adaptation to HMs by the integral response of physiological and biochemical adaptive parameters in various plant life forms. Materials and methods. Seeds of ruderal species from biotopes with a moderate level 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 7-14 days of the experiment, the HM-sensitive adaptive parameters of plants were measured. Descriptive statistics was made in the MS Excel program. The significance of the differences between the variants of the experiment was assessed by the Duncan test at p ≤ 0.05. To assess the plants adaptation degree to HMs, the adaptation index (IAHM) was used. Results and conclusions. The toxic HMs effect on plants increased with an increase in the metal concentration in the environment. Among the studied life forms, therophytes are most adapted to HMs ions. Many wild-growing forms are characterized by increased adaptation to Zn2+ and Ni2+ ions in the. Annual plants were the most tolerant to the HMs while polycarpic perennials implement a metal resistance strategy.

Keywords

• adaptation index
• plant life forms
• heavy metals
• mono- and polycarpic plants