Abstract:

In order to discover the agricultural activity and fungicidal ingredient in the leaves of Magnolia grandiflora Lima and provide scientific proofs of its exploitation and utilization, antifungal activity of the extracts from leaves of Magnolia grandiflora. Lima with ethanol and different solvents were studied. Using a mycelial growth method, the fungistasis of the extracts with ethanol against eight agricultural fungi were investigated in this study. The results showed that the extracts have strong antifungal activity against the tested pathogenic fungi. The inhibition rate of 81.4% and 52.1% with the concentration of 1.0 mg/ml, against Valsa mali and Alternaria brassicicola, respectively. With the concentration of 5.0 mg/ml, the inhibition rate of more than 50% against Gibberella zeae, Fusarium oxysporum f.sp.vasinfectum and Physalospora piricola nose. The EC50 of ethanol extracts against V.mali and Alternaria brassicicola were 0.04 mg/ml and 1.20 mg/ml. The ethanolic extract was fractionated using solvents of increasing polarity, the n-hexane and ethyl acetate fraction had stronger antifungal activities than that of extracts by solvents n-butanol and water. The EC50 of n-hexane and ethyl acetate fraction against V. mali was 0.03 mg/ml and 0.11 mg/ml, respectively. These indicated that most of the activity components were distributed in the n-hexane and ethyl acetate fraction, and the n-hexane and ethyl acetate partition would be acted as the emphases in the further study.