A study of some morphophysiological characteristics in water mint (Mentha aquatica L.) under lead and cadmium stress

Heavy elements of lead and cadmium are toxic and common pollutants of the soil which with effect of process and function plant affect on the sustainable production of plants. Therefore, in this study, lead and cadmium stress was studied on some growth parameters of water mint aromatic plant (Mentha aquatica L.). Treatments included different concentrations of lead (0, 125, 250, 375 and 500 mg/kg) and cadmium (0, 5, 10, 15 and 20 mg/kg) in two separate experiments. A completely randomized design with four replications was conducted at Sari Agricultural Sciences and Natural Resources University. Water mint with five plant densities were planted in pots containing heavy elements. After two months, plant height, number of leaf, leaf area, greenness index, total chlorophyll and shoot fresh weight were measured. In general, lead and cadmium stress reduced the average of measured traits. As the elements increased, the decreasing trend was observed in the studied traits. In other words, the least amount of these traits was related to the highest levels of lead and cadmium treatment. In fact, lead and cadmium elements with effect on morphological traits lead to a series of physiological changes in water mint, which ultimately leads to reduced yield in the plant. Due to the lack of burn, chlorosis and leaves abscission, water mint is considered as a plant that is resistant to lead and cadmium. But in terms of food security, it is necessary to pay attention to pollution of water mint with heavy elements.