Blueberry (genus vaccinium V5) leaves were collected from Qingpu Modern Agricultural Park (Shanghai, China) in 2014 at commercial mature stage of the blueberry fruit and separated by hands to get rid of debris. The leaves were immediately freeze-dried (Freezone 2.5L Triad, Labconco Inc., USA) and stored at -80°C until usage. All standards were obtained from Sigma Aldrich (St. Louis, USA) and all chemical agents were purchased from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). Nutrient broth and plate count agar were obtained from Beijing Land Bridge Technology Co., Ltd (Beijing, China). Potato dextrose agar medium was from Hangzhou Tianhe Microorganism Reagent Co., Ltd. (Hangzhou, China).