Preliminary screening and characterization of fungi isolated from forest soil as biocontrol agent against Ganoderma boninense

Abstract

Aims: The objective of this study is to investigate the potential of fungi isolated from forest soil as biocontrol against Ganoderma boninense, the causal pathogen of basal stem rot disease in Elaeis guineensis Jacq. (oil palm). Methodology and results: Total 195 isolates were isolated from 20 soil samples collected from Crocker Range of Sabah and 54 fungal isolates were identified with 14 of them showed Percentage Inhibition of Radial Growth (PIRG) greater than 50%. A potential fungi (F15) with PIRG of 84.85% was later identified as Penicillium simplicissimum using molecular technique. Microscopy examination on P. simplicissimum and G. boninense interaction showed the evidence on the damage of pathogen hyphae when challenged by P. simplicissimum. The secondary metabolites of P. simplicissimum which may possibly contribute to this observation were later extracted using hexane, ethyl acetate and acetone and the extracts were tested in agar dilution bioassay (0.2 mg/mL to 1.0 mg/mL) against the pathogen. Ethyl acetate extract gave the highest inhibition to G. boninense (14.12 % in 0.4 mg/mL of ethyl acetate extract). Conclusion, significance and impact of study: This is the first report, on the bioactivity of P. simplicissimum isolated from Crocker Range of Sabah against Ganoderma boninense, the causal pathogen of basal stem rot disease. Overall, our results indicated that P. simplicissimum has the potential to be further investigated as a biocontrol agent against G. boninense.