Response of antioxidant defense mechanism and wheat yield changes to drought stress with application of different concentrations of nano-silicone and nano-titanium

The importance of crop production stability during water shortage is increasingly serious due to the growing population in the world. Regarding possibility effects of nano-titanium and nano-silicone on wheat growth and development under drought stress conditions, the present study was conducted using split plot experiment in a randomized complete block design with three replications in the Plant Production and Genetics department, Faculty of Agriculture, University of Maragheh. Differenr watering levels (irrigation in 90% of field capacity as non-stress condition, irrigation in 75% of the field capacity as a medium stress and irrigation in 50% of the filed capacity as a severe stress) was arranged in main plot and application of nano-particles (dry seed, 0.5%, 1%, 1.5%, 2% of nano-titanium and nano-silicone spraying) was arranged in sub-plots. The results of analysis of variance showed that interaction effect of nano-particles application and drought stress on dry weight, leaf area, chlorophyll a, chlorophyll b, carotenoid, total chlorophyll, 1000 grain weight, superoxide dismutase, Cu/Zn-SOD, Mn- SOD, Fe-SOD, ascorbate peroxidase, guaiacol peroxidase, hydrogen peroxide, malondialdehyde, proline at 1% probability level, and the activity of catalase were significant at 5% probability level. The mean comparison showed that the highest impact of nano-titanium and nano-silicon on the antioxidant system and chlorophyll and hydrogen peroxide levels was recorded for watering treatments at 50 and 70% of the field capacity and high levels of those materials (1.5 and 2%). According to the chlorophyll content, leaf area, dry weight and yield results under drought stress conditions, application of 2% nano-titanium had the most beneficial effects, compared to the silicon on plants and it can be recommend as a result of this study for similar experimental conditions.