Rapid detection of Ganoderma disease of coconut and assessment of inhibition effect of various control measures by immunoassay and PCR

Abstract

Molecular and immunological methods were applied for detecting the <i>Ganoderma</i> disease of coconut. Polyclonal antibodies (PAbs) raised against basidiocarp protein of <i>Ganoderma</i> were used. For the polymerase chain reaction (PCR) tests, the primer generated from the internal transcribed spacer region one (ITS 1) of ribosomal DNA gene of <i>Ganoderma</i>, which produced a PCR product of 167 bp in size, was used. Apparently healthy palms in two coconut gardens were tested for <i>Ganoderma</i> disease by ELISA test using basidiocarp protein antiserum. Field trials were laid out in these early-diagnosed palms for the management of the disease. Based on the ELISA results, <i>Pseudomonas fluorescens</i> + <i>Trichoderma viride</i> with chitin amended treatments arrested the multiplication of the pathogen and within 6 months showed an optical density (OD) below the level of infected plants. Integrated Disease Management (IDM) and fungicide tridemorph treated palms showed OD values below infection level within 7 months, and <i>T. harzianum</i> and <i>P. fluorescens</i> + <i>T. viride</i> treated palms showed OD values below infection level in 8 months.