Mei Lieng Lo is an assistant research officer at the Sarawak Tropical Peat Research Institute. She received her bachelor's degree in plant science from the University of Malaysia Sarawak and is currently pursuing her master's degree in plant pathology at the same institution. Her research involves characterizing a phytopathogen from Sarawak, Ganoderma boninense, which causes basal stem rot in oil palm (Elaeis guineensis). This research aims to identify potential reference isolates that can be used in future studies to acquire new insights for the development of long-term and sustainable management strategies for Ganoderma disease.
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Utilization of infected oil palm seedlings to differentiate the aggressiveness of Ganoderma boninense isolates from Sarawak
M. L. LO, T. A. VU THANH, F. MIDOT, S. Y. L. LAU, W. C. WONG, H. J. TUNG, M. S. JEE, M. Y. CHIN, L. MELLING
Sarawak Tropical Peat Research Institute (TROPI), Lot 6035, Kuching-Kota Samarahan Expressway, 94300 Kota Samarahan, Sarawak, Malaysia
Basal stem rot, caused by Ganoderma boninense, impacted oil palm productivity, resulting in annual losses of up to $500 million. The aggressiveness of Ganoderma species isolated from different geographical regions varies significantly, and this variation affects the rate of disease spread and host damage. Ganoderma boninense aggressiveness levels are frequently differentiated using disease severity index (DSI), followed by a culture-based method for disease confirmation that may not yield reliable results or be feasible in all cases. We used vegetative growth measurement of infected oil palm seedlings together with DSI to differentiate the aggressiveness of G. boninense isolates. To confirm disease presence, we employed scanning electron microscopy and molecular identification of fungal DNA from both infected tissue and fungi isolated from Ganoderma selective medium. Two-month-old oil palm seedlings were infected with G. boninense isolates (2, 4A, 5A, 5B, and 7A) from Sarawak. Based on their DSI, the isolates were grouped into three categories: highly aggressive (4A and 5B), moderately aggressive (5A and 7A), and less aggressive (2). Isolate 5B was identified as the most aggressive and the only one that causes seedling death. Finally, the combination of conventional and molecular approaches in disease confirmation enables precise disease detection.