Effects of poplar buds as an alternative to propolis on postharvest diseases control of strawberry fruits

BACKGROUND: Botrytis cinerea and Rhizopus stolonifer, two main postharvest pathogens, cause great loss of strawberry fruits. Here, the effects of poplar buds extracts, a main plant source for Chinese propolis, on disease control were investigated in vitro and in vivo. RESULTS: The HPLC profile of poplar buds ethanol extract (PBEE) was almost identical to that of propolis ethanol extract (PEE), with the active flavonoids identified as pinocembrin, chrysin and galangin. PBEE exhibited similar inhibitory activities on spore germination of both pathogens compared with PEE, and PBEE also strongly inhibited the mycelial growth of the pathogens. In vivo, PBEE could effectively reduce decay of strawberry fruits stored at 13 degrees C. Although the weight loss was slightly increased, the contents of total soluble solid, titritable acid, vitamin C and total anthocyanins were significantly higher in PBEE treated fruits than those of the control. CONCLUSION: PBEE had the similar antifungal activity with propolis and had great potential as an alternative to propolis to control strawberry fruits diseases. (C) 2015 Society of Chemical Industry