Physiological Studies on the Toxicity of Nano and Bulk Nickel Oxide in Germinating Seedlings of Fennel (Foeniculum vulgare Mill.)

The effect of nanoparticles on living organisms is not well understood yet. The physicochemical properties of nanoparticles enhance the use of nanotechnology in various fields. In this study, the effect of different concentrations of nano and bulk nickel oxide (0, 10, 20, 50, 100, 200, 400, 600, 800, and 1000 ppm) on fennel seed germination and growth was tested in a randomized complete design with four replications. After 14 days of seed treatment, germination factors (germination percent, relative germination percent, mean germination time, germination rate, germination index, and weight germination index) were measured. In general, low nano concentrations and medium bulk concentrations on fennel seed growth showed stimulating effects, while high nano and bulk concentrations showed toxic effects. Therefore, exposure of fennel seeds to low concentrations of NiO nanoparticles and medium concentrations of bulk NiO stimulated seed germination. These concentrations can be used as a new approach to overcome seed germination problems of some plant species, especially medicinal plants such as fennel.