In vitro screening of biocontrol and biodegradation potential of selected hymenomycetes against Ganoderma boninense and infected oil palm waste

The antagonistic and enzymatic activities of non‐pathogenic hymenomycetes naturally occurring on oil palm (Elaeis guineensis) trunks were assessed to determine their potential as biocontrol agents against G. boninense. Twenty‐five Basidiomycota were isolated on a Ganoderma‐selective medium and identified using internal transcribed spacer (ITS) sequencing. The three fungi with potentially higher antagonistic activity against G. boninense, based on the percentage inhibition of radial mycelial growth (PIRG) in dual culture, were Pycnoporus sanguineus (84%), Trametes lactinea (82%) and Grammothele fuligo (81%). In addition to these three isolates, Lentinus tigrinus and a Rigidoporus sp. were also able to invade sterilized oil palm blocks previously colonized by G. boninense despite having lower PIRG values. Colonization of oil palm blocks by G. fuligo, P. sanguineus, Rigidoporus sp., T. lactinea and L. tigrinus resulted in mass losses of 32.50, 30.78, 27.64, 25.20 and 19.33%, respectively, probably due to an ability to produce one or more lignocellulolytic enzyme. Further work is needed to determine the enzymatic degradation potential of these fungi under natural conditions and their possible use in the prevention of colonization of oil palm by G. boninense.