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Ganoderma boninense is a fungal pathogen that causes basal stem rot (BSR) disease in oil palm. Being a serious disease problem to the oil palm industry, monitoring and detecting the pathogen is of the utmost importance to reduce disease spread and facilitate effective management strategies. Because the traditional culture-based assay is time-consuming, labor-intensive, and required special skills in mycology, plant pathologists are turning to more accurate, sensitive, and fast methods such as molecular techniques. In this study, polymerase chain reaction (PCR) assays were developed to detect pathogenic Ganoderma species causing BSR disease in oil palm using a primer designed based on the ribosomal DNA internal transcribed spacer (ITS) region. The effectiveness of conventional and real-time PCR assays was analyzed compared to the traditional isolation-based assay. For artificially inoculated oil palm plantlets, consistent detection of G. boninense was observed. Real-time PCR assay has shown to be more sensitive and rapid in detecting G. boninense in field samples and could potentially serve as a validation tool to other detection techniques for the implementation of effective disease control measures. [ABSTRACT FROM AUTHOR]

Bud rot disease is a damaging disease of oil palm in Colombia. The pathogen responsible for this disease is a species of oomyctes, Phytophthora palmivora which is also the causal pathogen of several tropical crop diseases such as fruit rot and stem canker of cocoa, rubber, durian and jackfruit. No outbreaks of bud rot have been reported in oil palm in Malaysia or other Southeast Asian countries, despite this particular species being present in the region. Analysis of the genomic sequences of several genetic markers; the internal transcribe spacer regions (ITS) of the ribosomal RNA gene cluster, beta-tubulin gene, translation elongation factor 1 alpha gene (EF-1α), cytochrome c oxidase subunit I & II (COXI and COXII) gene cluster along with amplified fragment length polymorphism (AFLP) analyses have been carried out to investigate the genetic diversity and variation of P. palmivora isolates from around the world and from different hosts in comparison to Colombian oil palm isolates, as one of the steps in understanding why this species of oomycetes causes devastating damage to oil palm in Latin America but not in other regions. Phylogenetic analyses of these regions showed that the Colombian oil palm isolates were not separated from Malaysian isolates. AFLP analysis and a new marker PPHPAV, targeting an unclassified hypothetical protein, was found to be able to differentiate Malaysian and Colombian isolates and showed a clear clade separations. Despite this, pathogenicity studies did not show any significant differences in the level of aggressiveness of different isolates against oil palm in glasshouse tests. [ABSTRACT FROM AUTHOR]