Exogenous Application of Green Titanium Dioxide Nanoparticles (TiO 2 NPs) to Improve the Germination, Physiochemical, and Yield Parameters of Wheat Plants under Salinity Stress.

Agriculture is the backbone of every developing country. Among various crops, wheat ( Triticum aestivum L.) belongs to the family Poaceae and is the most important staple food crop of various countries. Different biotic (viruses, bacteria and fungi) and abiotic stresses (water logging, drought and salinity) adversely affect the qualitative and quantitative attributes of wheat. Among these stresses, salinity stress is a very important limiting factor affecting the morphological, physiological, biochemical attributes and grain yield of wheat. This research work was carried out to evaluate the influence of phytosynthesized TiO 2 NPs on the germination, physiochemical, and yield attributes of wheat varieties in response to salinity. TiO 2 NPs were synthesized using TiO 2 salt and a Buddleja asiatica plant extract as a reducing and capping agent. Various concentrations of TiO 2 nanoparticles (20, 40, 60 and 80 mg/L) and salt solutions (NaCl) (100 and 150 mM) were used. A total of 20 mg/L and 40 mg/L improve germination attributes, osmotic and water potential, carotenoid, total phenolic, and flavonoid content, soluble sugar and proteins, proline and amino acid content, superoxide dismutase activity, and reduce malondialdhehyde (MDA) content at both levels of salinity. These two concentrations also improved the yield attributes of wheat varieties at both salinity levels. The best results were observed at 40 mg/L of TiO 2 NPs at both salinity levels. However, the highest concentrations (60 and 80 mg/L) of TiO 2 NPs showed negative effects on germination, physiochemical and yield characteristics and causes stress in both wheat varieties under control irrigation conditions and salinity stress. Therefore, in conclusion, the findings of this research are that the foliar application of TiO 2 NPs can help to improve tolerance against salinity stress in plants.