The Toxicity of Natamycin to Alternaria Nees ex Wallr.and Physiological Activity of Fresh-keeping Dong Jujube Using Natamycin Treatments

The toxicity of natamycin to Alternaria Nees ex Wallr.was tested in laboratory and the effects on physiological activities and biochemical attributes of Dong jujube fruit during low temperature storage were studied,and suitable concentration for storage of Dong jujube fruit were screened.The results showed that the EC50 and EC90 value of natamycin to Alternaria Nees ex Wallr.were 39.56 and 208.5 mg/L,respectively.The EC90 value of natamycin showed no significant differences with that of iprodione and myclobutanil.Natamycin at 500~1 000 mg/L could inhibit the fortification of MDA,increase the activity of PG and PAL,and it had the best effects on keeping the firmness,and inhibit the decline of soluble solid content and Vc content of Dong jujube.After treated with natamycin and stored for 60 and 100 days,the commodity rate of Dong jujube were 87.3% and 75.0% respectively,which were significantly higher than those of the control.