ABSTRACT
Aims@#The development of an effective biocontrol formulation for inhibition of Ganoderma boninense, a well-known destructive pathogen in oil palm plantation is important to prolong the palm’s lifespan and reduce the losses due to this disease. In this paper, we present some new bioformulations with combination of different types of biocontrol agents in managing basal stem rot (BSR) disease. @*Methodology@#The effectiveness of the treatments designed as T1 (Trichoderma harzianum + Lecanicillium spp. + Streptomyces sundarbansensis + Pseudomonas aeruginosa), T2 (Penicillium simplicissimum + Lecanicillium sp. + S. sundarbansensis + P. aeruginosa), T3 (P. simplicissimum + P. aeruginosa) and T4 (LEStani®) was evaluated through treatment on the oil palm seedlings artificial infected by G. boninense and the results were expressed in disease severity index (DSI), bole severity index (BSI) and ergosterol content.@*Conclusion, significance and impact of study@#All tested treatments (T1-T4) managed to control the severity of the Ganoderma infection from continuously increasing when the treatments were applied either one month before or after artificial inoculation. The disease severity of infected seedlings without treatments had increased for almost 2-fold at the end of the trial. Moreover, T1 had the greatest inhibition of G. boninense with the lowest ergosterol content (a bioindicator of Ganoderma colonization) detected (676.67 g/mL), which is about 1.9-fold lower than control (1273.33 ug/mL) without treatments and a BSI score of 1. Based on the effectiveness among the four tested biocontrol formulations, T1 is the most promising formulation to be further evaluated in the field for control of BSR disease. However, more research is needed in the future to estimate the effective amount for application in open environment.
Subject(s)
Palm Oil , Biological Control Agents , GanodermaABSTRACT
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.
ABSTRACT
Aim To investigate the chemical compo-nents and antibacterial and nematicidal activity of en-doparasitic fungi ThF-1 1 of Tripterygium hypoglaucum (Levl.)Hutch.Methods The endophyte ThF-1 1 was isolated,purified and identified based on fungal ITS sequence.The chemical components were isolated and identified with column chromatography and NMR spec-trometer,respectively.The nematicidal and antibacte-rial activity was investigated by biological active meth-od and inhibition zone method.Results The endo-phyte ThF-1 1 was identified as Penicillium simplicissi-mum,the compounds were identified as Penicillic acid [1 ],2,4-dimethoxy-6-methylphenol [2]and 5 (6)-dihydropenicillic acid [3 ] based on spectral data. Compound [1 ]showed significant activity against Cae-norhabditis elegans in a dose-dependent manner,and had antibacterial activity to Escherichia coli,Bacillus cereus,Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa.Conclusion These com-pounds are firstly isolated from endophyte ThF-1 1 of T. hypoglaucum (Levl.)Hutch.Compound [1 ]shows strong nematicidal activity and antibacterial activity, and is worth further studying and developing.