Potential application of TiO2 nanoparticles to improve the nutritional quality of strawberry cv. Camarosa under drought stress

Strawberry (Fragaria x ananassa Duch) is a most important plant that exhibits sensitivity to water stress, primarily because of its superficial root system. The objective of this study was to assess the potential of applying TiO2 nanoparticles (NPs) at concentrations of 0, 10, 20, and 30 mg L - 1 as a foliar treatment. The investigation aimed to evaluate the effects of these treatments under different irrigation conditions, namely full irrigation (FI), partial root zone drying (PRD), and sustained deficit irrigation (SDI), on the quantitative and qualitative characteristics of strawberries. Results showed that the fruit firmness of SDI plants was reduced by 25.2 %, 25.2 %, and 21.5 % in the concentration of 10, 20, and 30 mg L -1 TiO2 NPs, respectively, compared to the FI. According to the results, PRD alone increased most color indices by applying water stresses, an increase in fruit carbohydrate was observed under treatment with TiO2 at different concentrations. Increasing TiO2 concentration increased flavonoids at plant under PRD and SDI. Regarding anthocyanin changes in fruit, this trait increased by raising drought stress by 240.6 and 281.8 % under PRD and SDI strategies, respectively. As the drought stress increased, ascorbic acid decreased by 1.9 % and 2.41 % respectively in PRD and SDI treatments compared to FI. Application of TiO2 NPs is a convenient strategy for improving productivity of plants under drought stress. Generally, considering the results, foliar application of TiO2 under PRD is recommended to improve physicochemical traits under drought stress.