Antifungal activity of the osthol derivative JS-B against Phytophthora capsici

Abstract

JS-B (C₁₂H₁₀O₃) is a derivative compound of osthol. The antifungal properties of JS-B were tested against 10 economically important plant pathogens. JS-B was effective in inhibiting the mycelial growth of Phytophthora capsici, and its inhibition on different stages of the life cycle of P. capsici was observed. The 50% effective concentration (EC₅₀) of JS-B on mycelial dry weight and zoospore germination of P. capsici was 43.74 and 86.03 μg/ml, respectively. The rupture of released zoospores induced by JS-B was reduced by the addition of 100 mM glucose. The ultrastructural study showed that JS-B caused destruction of most of the mitochondrions, the concentration of cell nuclear, and the existing vesicles. When compared with dimethomorph, the activity of JS-B on P. capsici was determined under pot conditions. The result showed that JS-B has a curative effect on pepper blight.

Keywords:

• antifungal
• pepper blight
• Phytophthora capsici
• ultrastructure

Acknowledgements

This work was financially supported by the Innovation Fund for Agricultural Sciences and Technology of Jiangsu, China (No. CX(08)125).