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

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 86.03g/ml, respectively. The rupture of released zoospores induced by JS-B was reduced by the addition of 100mM 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.