Effect of postharvest methionine treatment on blue mould and reactive oxygen metabolism in peach fruit

Peach fruit was used as materials to study the effects of postharvest methionine treatment on lesion development of peach fruit inoculated with Penicillium expansum.The optimum concentration of methionine was selected according to the lesion diameter,and then to analyzing the effect of methionine on the reactive oxygen metabolism in peach fruit.The results indicated that methionine at the concentration of 15 mmol/L effectively inhibited lesion development of peach fruit inoculated with P.expansum.The results also indicated that methionine treatment significantly( p≤0.05) increased the content of ascorbic acid(AsA) and glutathione(GSH),enhanced the activity of glutathione reductase(GR),ascorbate peroxidase(APX) and catalase(CAT) and the content of H_2O_2 in peach fruit. The results suggest that postharvest methionine treatment could improve the resistance of peach fruit against P.expansum by regulating the reactive oxygen metabolism.