Postharvest Application of Sodium Selenite Maintains Fruit Quality and Improves the Gray Mold Resistance of Strawberry

Strawberry is a worldwide demanded edible fruit with high economic and nutritional value; however, a very short storage life largely limits its supply and marketing. In this study, strawberries were treated using sodium selenite with different concentrations (6, 12, 18, and 24 mg/L), and the postharvest fruit quality and resistance to Botrytis cinerea were substantially assessed. Among all concentrations, 12 mg/L Se was the most effective treatment, which maintained fruit skin brightness, reduced natural decay incidence, severity, and weight loss, increased the Se content in fruit, and thus maintained the postharvest fruit quality of the strawberry. Furthermore, strawberries treated with 12 mg/L Se had lower flavonoid, phenolic, anthocyanins, proanthocyanidins, H2O2, and O-2(-) contents compared to the control and, correspondingly, lower antioxidant capacity; moreover, 12 mg/L Se treatment decreased the decay incidence and severity caused by the infection of B. cinerea. Collectively, our findings may provide a reference for developing safe and environmentally friendly alternative methods to sustain quality and manage gray mold in postharvest strawberries as well as other horticultural crops.