Improving seed germination, growth, and biochemical characteristics of corn seedlings via the application of iron oxide nanoparticles synthesized from oregano (Origanum vulgare)

TIn order to evaluate the effect of iron nanooxide synthesized from oregano on germination, growth and biochemical characteristics of corn seedlings, an experiment was carried out in a randomized complete block design with three replications. Experimental factors included synthesized iron oxide nanoparticles and the application methods of iron oxide nanoparticles. The results showed that iron oxide nanoparticles had a significant effect on germination, growth, and biochemical characteristics of seedlings. The highest germination rate, vigor index, seedling dry weight, and length were achieved with the application of 240 mg L-1 of iron oxide nanoparticles. Among the nanoparticle application methods, seed priming compared to the method of adding them to the planting medium had a greater effect on improving germination, growth, and increasing the vigor index. Using 240 mg L-1 of iron oxide nanoparticles as priming resulted in the highest germination percentage, germination synchrony index, mean daily germination, and the lowest MGT. In the case of adding nanoparticles to the planting medium, although it had less effect than the priming method, adding 360 mg L-1 of iron oxide nanoparticles to the planting medium also caused a significant increase in corn germination. The use of different concentrations of iron oxide nanoparticles in both methods of nanoparticle application caused a significant increase in the activity of antioxidant enzymes in seedlings. Therefore, the use of a concentration of 240 mg L-1 of iron oxide nanoparticles as a priming can be suggested to improve germination, growth, and biochemical characteristics of seedlings.