Hydrogen peroxide treatment promotes early ripening of Kyoho grape

Background and Aims Reactive oxygen species are involved in fruit ripening. Here, we investigated the role of hydrogen peroxide (H2O2) in promoting grape (Vitis vinifera L.) berry ripening. Methods and Results Solutions of 100, 300 and 500 mmol/L H2O2 were sprayed on Kyoho bunches 25 days post anthesis (dpa). All treatments promoted early ripening of berries, although the 300 mmol/L treatment was the most effective; at this concentration, Kyoho berries ripened 20 days earlier than the Control. Ripening-related physiological indexes, such as berry diameter and firmness, anthocyanin, sucrose and malonaldehyde concentration, and catalase, cellulase and polygalacturonase activity, were similar for the H2O2-treated and Control berries. The TSS concentration of berries treated with 300 mmol/L H2O2 was significantly higher than that of Control berries throughout the experiment. Superoxide dismutase activity in H2O2-treated berries was significantly higher than that in Control berries at 35 and 70 dpa. All H2O2 treatments enhanced the ascorbic acid concentration of berries. Conclusions Exogenously applied H2O2 promotes the early ripening of Kyoho berries. Significance of the Study This study provides a simple, efficient, safe, economical and environmentally friendly medium to promote early ripening of grape berries.