Effects of extraction method on amtifugal activity of plant extract to Peronophythora litchi

Eight kinds of plant extracts were obtained by ultrasonic extraction and organic solvent soaking method，and their inhibitory effects on mycelial growth and sporangial germination of Peronophythora litchi were tested. Results showed that the effect by ultrasonic extraction was better than that by soaking extraction.The extracts from Cortex phellodendri either by ultrasonic or by soaking extraction had the strongest anti-fungal activities among the 8 extracts. At the concentration of 5 mg/mL，the inhibition rate of extracts from C. phellodendri with ultrasonic extraction on mycelial growth was 100%，and on the sporangium germination was 61.77%；that of the extracts from C. phellodendri with saoking extraction on mycelial growth was also 100%，and on the sporangium germination was 41.76%. The EC50 values of extracts from C. phellodendri with ultrasonic extraction and soaking extraction on inhibiting mycelial growth of P. litchi were 585.62 μg/mL and 685.65 μg/mL，respectively. Ultrasonic extraction method was suitable for extracting plant-sourced anti-fungal substances，the extracts from C. phellodendri had high inhibitor activities on P. litchi.