Influences of PPO Inhibitors on Browning in Phalaenopsis Explants

The effects of Polyphenol oxidase(PPO) activity inhibitors supplemented to reaction buffer at different concentrations showed that ascorbate acid and Cys complete inhibited PPO activity at 0.5 mmol/L.Adding PPO activity inhibitors to media at different concentrations,the results showed that 300 mg/L citric acid and 100-200mg/L NaHSO3 could reduce the browning of Phalaenopsis explants.Soaking explants with PPO activity inhibitors,it showed that 50 mg/L ascorbate acid gave the best result for browning inhibition and PPO activity was lower than that of control before explants browning happened.