Development of Diagnostic Methods for Detecting Ganoderma-infected Oil Palms

Two diagnostic methods have been applied for detecting the plant pathogenic fungus Ganoderma\ a basi! diomycete\ causing the basal stem rot "BSR# disease of oil palms[ One approach was the use of polyclonal antibodies "PAbs# raised against mycelial proteins of a single Ganoderma isolate and a mixture of nine di}erent Ganoderma isolates[ Both PAbs could detect Ganoderma in diseased oil palm root tissue by applying an indirect enzyme!linked immunosorbent assay[ Low cross!reac! tions were observed with the _ve mainly occurring sap! rophytic fungi which could be isolated from diseased oil palms and were used as negative controls[ The other approach was based on the polymerase chain reaction "PCR# in order to increase the sensitivity of the Gan! oderma detection[ The primers were generated from the internal transcribed spacer region 0 of rDNA of Gan! oderma boninense and produced an PCR product of 056 bp in size[ Fungal isolates and oil palm root samples were processed for PCR by three di}erent DNA extrac! tion methods[ The most suitable extraction procedure was a simple alkaline extraction method[ For a practical approach\ a semiquanti_cation was performed by assess! ing the PCR sensitivity limits of pure culture Ganoderma and naturally infected root samples[