Antifungal Activity of Monoterpenes against Botryosphaeria dothidea

The development of natural plant extracts and essential oils will assist to decrease the negative effects of synthetic chemicals. The antifungal activity of 20 pure monoterpenes was assessed their efficacy against Botryosphaeria dothidea. 20 compounds were investigated the antifungal activity against B. dothidea at the concentration of 400 mu g.mL(-1). And components were used to the future test, which of the antifungal rate is greater than 50% against B. dothidea. Results from antifungal tests revealed that cuminaldehyde, beta-citronellol, nerol, geraniol, citral and alpha-terpineol exhibited strong antifungal effect against B. dothidea. In addition, the antifungal activity of cuminaldehyde, beta-citronellol, and geraniol had a highest effect toward B. dothidea with LC50 values of 105.15, 135.73, 132.69 mu g.mL(-1), respectively. In addition to the antagonistic effect of geraniol/beta-citronellol (1/2) mixture, the combination of other compounds has synergistic effect on B. dothidea. The present results indicated that cuminaldehyde, geraniol, and beta-citronellol are promising antifungal effect against B. dothidea and could be useful in the search for new natural fungicide. Several high activity monoterpenes and some combined with two monoterpenes were identified, and provided a rationale for pursuing further research on the fungicide and enhanced efficacy by the combined of fungicide.