Antagonistic capacity of dark septate endophytes (DSE) against Ganoderma boninense from oil palm (Elaeis guinensis Jacq.)

Abstract

Ganoderma boninense, a causal agent of basal stem rot, as one of the major problems in oil palm plantation in Indonesia. The potential of dark septate endophytes (DSE) as biocontrol agents for G. boninense is not widely studied. Therefore, this study aims to screen DSE strains to obtain high antagonistic strains. The antagonistic capacity of 10 DSE strains was determined based on the growth inhibition in the dual culture, and volatile compounds challenge against G. boninense, in vitro. Volatile compound profiling of selected DSE strains that showed the highest challenge capacity was done using Pyrolysis Gas Chromatography-Mass Spectrometry. Among 10 DSE strains tested, TKC 2.2a had the highest percentage of G. boninense inhibition in dual cultures and the volatile compound challenge. This strain inhibited better if grown in media seven days earlier than grown simultaneously with G. boninsense. The volatile compounds of 14 days old TKC 2.2a were of 2H-1-Benzopyran-7-ol, 3,4-dihydro-5-methoxy-6-methyl-2-phenyl; 4-Allyl-2,6-dimetho-xyphenol; and hexa-decanoic acid, which were reported as having either antimicrobial or antifungal activities. These results indicate that DSE TKC 2.2a can be a candidate for a biocontrol agent against G. boninense in oil palm, depending on further research on its ability to reduce basal stem rot symptoms.