Effect of Osthol on the Invasion of Sphaerotheca fuliginea

The effect of osthol on the development of Sphaerotheca fuliginea was studied by detached leaves.The results showed that 6 days after inoculation,the disease index was 68.89 in the control,while that was only 15.56 in the treatment with osthol at 100 μg/mL.The number of interaction sites with H2O2 accumulation was strongly decreased in the leaves treated with osthol. Osthol also depressed the growth of mycelia.The average colony length was about 400 μm in the control,while that was only 122 μm in the treatment with 100 μg/mL osthol.Osthol could also depress conidiation of powdery mildew.