Determination of morphological and physiological changes and phytoremediation ability of pot marigold (Calendula officinalis) in zinc (Zn+ 2) toxicity conditions

In this study, the effects of zinc toxicity and phytoremediation potential of pot marigold (Calendula officinalis) were investigated. The studies were carried out in two main stages as seed germination and plant growth by using five different zinc concentrations (0, 250, 500, 750 and 1000 ppm). In the first stage of the study, seed germination and early seedling growth were investigated in two cultivars (Bon Bon and Gitana). At the end of the experiment, the inhibitory effects of zinc treatments in both cultivars were observed in the seedling development stage rather than the germination stage. In the second stage, the experiment was carried out in Zn applied potted soil. Bon Bon cv. was using as plant material and morphological and physiological parameters of plants were evaluated. At the end of the study, as a result of Zn treatment, plant growth parameters, chlorophyll content (total chlorophyll, chlorophyll a chlorophyll b) and leaf relative water content decreased; turgor loss, ion leakage and membrane damage increased; size and number of stomata and content of some nutrients changed. The changes in zinc content revealed the phytoremediation capacity of pot marigold. As Zn concentrations increased, the amount of Zn removed by the plants from the soil increased. At the highest zinc level (1000 ppm), Zn content of shoots and roots were found 5 and 7 times higher respectively, comparasion to control treatment.