Impact of nanosized titanium dioxide on agronomical and physiological characteristics of annual medic (Medicago scutellata L.)

Abstract

In order to investigate the effect of exogenous application of nano- TiO2 on annual medic, a field study was conducted in a factorial design based on randomized complete blocks with four replications. The experimental treatments included six concentrations of nano-TiO2 (Control, 0.01%, 0.02%, 0.03%, 0.04%, 0.06% g/l) and spraying at two growing stages (pod stage and 10% flowering stage). Results showed that the effects of nano- TiO2 and spraying times on dry forage yield were significant (p<0.01). Nano-TiO2 spray appear to influence the malone dialdehyde (MDA) content (p<0.01). With increasing concentrations of nano-TiO2 the values of aforementioned measured variable significantly decreased. The activities of antioxidant enzymes, including catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) were affected by nanoparticle (p<0.01) and spraying times (p<0.01), as well as their interactive effect of two mentioned factors were significant in terms of guaiacol peroxidase (GPX) (p<0.01) activity and dry forage yield. Among different concentrations of nano- TiO2, 0.04% and 0.06% have the best effect on all traits. Totally, treatment with nano- TiO2 were more effective in the pod stage, compared to 10% flowering stage.