In Vitro Synergy Effect of Syringic Acid, Caffeic Acid and 4-hydroxybenzoic Acid against Ganoderma boninense

Abstract

This paper discusses the in vitro synergy effect of syringic acid, caffeic acid and 4-hydroxybenzoic acid which found in oil palm root. Experiments were observed for fourteen days, repeated at least three times and data were recorded daily. The synergy effect of the phenolics against Ganoderma boninense were expressed in inhibition of radial growth of G. boninense on PDA ameliorated with the combination of either two or three different phenolics with concentration of 0.5 to 2.5 mg/ml. Several combinations showed strong fungitoxicity effect to G. boninense. Combinations of 4-hydroxybenz oic acid, syringic acid and caffeic acid up to 2.5 mg/ml strongly inhibited the growth of G. boninense in comparison to the control. currently no effective cure for G. boninense infection in an existing stand. Preventive and ameliorative treatments which are commonly carried out show various degrees of effectiveness (13). Determination of total phenolic content in G. boninense infected and healthy oil palm roots showed susceptible palm roots at week four had low phenolic content, whereas week one had high phenolic content. Gallic acids concentrations decreased in the four weeks old roots of infected susceptible palms compared to healthy roots. Determination of total phenolic content in infected palm seedlings root (D X P) also showed low phenolic content compared to the non infected palm seedlings root. This indicate phenolic compounds are involved in oil palm resistance against Ganoderma (11).To identify the possibility of oil palm resistance against G. boninense in certain circumstances need further investigation. However, if resistance in oil palm against G. boninense is possible, it may contribute to tackling the problem. In a collaborative experiment to this research, we found syringic acid, caffeic acid and 4-hydroxybenzoic acid present in oil palm roots in natural condition or after elicitation. In this paper, we present the works on in vitro synergy effect of syringic acid, caffeic acid and 4-hydroxybenzoic acid to G. boninense.