Improvement of seed germination, growth and biochemical characteristics of corn seedlings via the application of copper oxide nanoparticles synthesized from eucalyptus (Eucalyptus camaldulensis)

In order to evaluate the effect of copper oxide nanoparticles synthesized from eucalyptus plant on seed germination, growth and biochemical characteristics of corn seedlings, and an experiment was carried out in a randomized complete block design with three replications at the University of Mohaghegh Ardabili in 2021. Experimental factors included synthesized copper oxide nanoparticles (0, 2.5, 5, 10, and 20 mg L-1) and the application methods of copper oxide nanoparticles (seed priming and adding to the planting medium). The results showed that in both methods of nanoparticle application (adding to the planting medium and priming), with the use of different concentrations of copper oxide nanoparticles, there was a significant increase in the percentage and speed of germination, average daily germination, germination synchronization index, strength index, length and dry weight. Corn seedlings and the reduction of the average germination time, the time for the germination of corn seeds to 50%. Among the methods of nanoparticle application, pretreating seeds with a concentration of 2.5 mg L-1 of copper oxide nanoparticles and adding a concentration of 5 mg L-1 of nanoparticles to the planting medium has the greatest effect on improving the percentage and speed of germination, seed synchronization index, length and dry weight. Seedlings and vigor index and decreased average seed germination time. The use of different concentrations of copper oxide nanoparticles in both application methods increased the activity of catalase, peroxidase, polyphenol oxidase and amino acid proline content compared to the control treatment. In general, it is recommended to use a concentration of 2.5 mg L-1 of copper oxide nanoparticles as a seed priming method and add a concentration of 5 mg L-1 of nanoparticles to the planting medium to improve seed germination, growth and biochemical characteristics of corn seedlings.