Inhibitory Effect of Plant Extracts on Fusarium oxysporum f. sp. cubense

Key words: 
• Fusarium oxysporum f.sp.cubense /
• inhibition /
• plant extracts

Abstract: Aqueous extracts from different parts of 20 plants were used to inhibit the growth of the strain Fusarium oxysporum f. sp. cubense based on the methods of mycelial growth and spore germination. Of the 20 plants Chinese leek,sunflower and lettuce exhibited the best antifungal effect on mycelial growth of the strain at an extract concentration of 200 m L·L^-1. Among these three plants,for the whole plant extract Chinese leek exhibited the best antifungal effect with an inhibition rate of 93. 6%,followed by the sunflower and the lettuce; for the root extract the sunflower exhibited the best antifungal effect with an inhibition rate of 88. 5%,followed by the lettuce and the Chinese leek; for the leaf and pseudostem extract these three plants had a poor inhibitory activity with an inhibition rate of less than 56%. Ten plants with the extract from the whole plant were all found to show inhibitory effect on conidial germination of F. oxysporum f. sp. cubense. When the extracts were mixed with spore suspension at an equal volume,Chinese leek with aqueous extract had best inhibitation against conidial germination of F. oxysporum f. sp. cubense,followed by the sunflower and lettuce,but no significant difference were observed in conidial inhibition between the Chinese leek and sunflowers.