EFFECTS OF DIFFERENT CONCENTRATIONS OF CADMIUM ON GROWTH AND MORPHOLOGICAL CHANGES IN BASIL (OCIMUM BASILICUM L.)

This study was conducted on four treatments (0, 3, 5 and 10 milligrams per liter of cadmium nitrate solution) and three replications in a completely randomized design. The morphological characteristics including fresh weight, dry weight, stem length, root length, leaf weight ratio, measuring index of the imposed stress, specific leaf area and water availability per unit leaf area, and the amount of cadmium in stems and roots were measured. By increasing cadmium treatment at 10 ppm concentration, the root growth varied between 3.47 and 1.93 cm and the lowest root growth belonged to the treatment at 10 ppm concentration measured 1.93 +/- 0.4 cm. The rising stem growth was also indicated. Fresh and dry weight analysis indicates their descending growth. The growth reduction was observed by increasing cadmium treatment at 10 ppm concentration in the study of the trait of weight and specific leaf area. Relative water content (RWC) of the leaves varies between 81 to 89 percent which represents the greatest amount of stress in the treatment at 10 ppm concentration. A notable decline in transport from the root to stem and a significant reduction in plant tolerance index were observed through the analysis of transfer factor and tolerance index in plants. The process of reducing metal transition from the root to stem has become slower by increasing the substance concentration. Basil can absorb and accumulate cadmium and its root is able to accumulate more quantity of the metal than its stem. The morphological signs of cadmium toxicity are remarkable through discolored roots, shortening the distance between nodes, creating an amorphous spots on the leaves, reducing the leaves extent and a slight pallor of the leaves.