Green synthesis and application of zinc oxide nanoparticles derived from Withania somnifera on tomato production and nutritional quality under saline conditions.

Food crops are enriching with nutrients and useful compound but their growth and fruit quality decline with NaCl stress. Plant based nanoparticle are promising to maintain biomass and good quality fruit even in saline soils. This study tested the efficacy of Withania somnifera nanoparticles to maximize tomato growth and nutrition retentions under 150 mM NaCl. Plant treated with the ZnO nanoparticles extracted with W. somnifera enhanced most of the growth parameters under both control and saline condition. Water relations such as maximum relative water content were increased about 84% and electrolyte leakage by 54% with 20 mgL-1 ZnO NPs at 150 mM NaCl compared to control. The Malondialdehyde (MDA) content increased with the increase in NaCl but this effect was decline with applying the biogenic ZnO nanoparticles. Total protein, catalase, peroxidase, ascorbate peroxidase, glutathione peroxidase and DPPH were increased with plants supplemented with 20 mgL-1 ZnO NPs at 150 mM NaCl. The chlorophyll a, chlorophyll b, total Chlorophyll and carotenoids increased substantially with 20 mgL-1 ZnO NPs 150 mM NaCl compared to control. The lycopene and total sugar content in tomato fruits also increases with increase of ZnO NPs. The mineral analysis such as zinc (6 folds), sodium (63%), calcium (6 folds), iron (6 folds), potassium (3 folds) and magnesium (8.3%) of treated tomato leaves and fruits also showed the prominent increase in the value of Zn and other elements. Application of ZnO nanoparticle from W. somnifera enhances biomass of tomato with nutrient retention and fruit yield to advance saline agriculture.