Chilling Injury Symptoms and Enzyme Activity Analysis of Lingwu Long Jujube

According to the observation to chilling injury symptoms of Lingwu Long Jujube, as well as the analysis to the enzyme activity related to the anti-adversity of plant in this paper, it is found that the disease will outbreak in 4-10 hours after low temperature pre-cooling, and the main symptoms include sinking semi-spherical dry spots and fibrosis of flesh. It is measured that the activity of polyphenol oxidase and phenylalnine ammonialyase in the diseased fruit is 0.34U and 101.689U separately, but the activity is 0.133U and 49.156U separately in healthy fruits, and there is a significant difference, but the difference of peroxidase is not significant. It laid the foundation for further research on relationship between chilling injury and metabolic pathway.