Disease Of Oil Palm Research Articles

Basal Stem Rot of Oil Palm - The Pathogen, Disease Incidence, and Control Methods.

Basal stem rot of oil palm caused by Ganoderma boninense is the most serious disease of oil palm in Malaysia, Indonesia, and other oil palm producing countries. Economic losses caused by the disease can be up to USD500 million a year. For many years, basal stem rot was found to infect older palms of over 25 - 30 years. Only in the 1950s, the disease began to appear in much younger palms (10 to 15 years old) and in the last decade or so, palms as young as 1 year were infected by the disease. The highest incidence occurs in coastal areas of Southeast Asia but the disease has now infected oil palm in inland areas, mainly oil palm planted in peat soils. Disease incidence is also high in areas previously growing coconut or forest. Basal stem rot infection and spread occur through root-to-root contact, and basidiospores that colonize the roots also play a role. In the early stages of infection by G. boninense, the pathogen behaves as a biotroph and later as a necrotroph, secreting cell wall-degrading enzymes and triggering host defense responses. Genes, gene products and metabolic pathways involved in oil palm defense mechanisms against G. boninense have been identified, and these metabolites have the potential to be used as markers for early detection of the disease. Integrated disease management used to control basal stem rot includes cultural practices, chemical control, and application of biocontrol agents or fertilizers. Early detection tools have also been developed which could assist in management of basal stem rot infections. Development of resistant or tolerant oil palm is still at an early stage, so the existing integrated disease management practices remain the most appropriate methods for managing basal stem rot of oil palm.

Validation of endophytic bacteria colonisation in tissue culture-derived oil palm plantlets via green fluorescent visualization

This study aimed to validate the colonisation capability of endophytic bacteria (EB) isolates, Bacillus cereus EB2 and Pseudomonas aeruginosa EB35, that previously exhibited their potentials as biological control agents (BCAs) against the Ganoderma spp., a pathogen for Ganoderma disease in oil palm. Here, we demonstrated a rapid method to determine the colonisation capacity of the selected EB using oil palm tissue culture plantlets and a green fluorescent protein (GFP) visual marker. Wounded plantlet roots were inoculated with GFP-tagged B. cereus EB2 and P. aeruginosa EB35 while the plantlets without EB inoculation served as controls. The GFP signals appeared as bright green spots or lines in the inoculated GFP-tagged EB cells in root and leaf plantlet tissues, respectively, under the confocal laser scanning microscopy (CLSM) 5 days post-inoculation. In contrast, there was no intense GFP spots in neither the control root nor leaf tissues. The cracks in the roots by wounding facilitated the entry of the GFP-tagged EB cells into root tissues, allowing for endophytically colonisation of the root and above-ground tissues. Subsequent result of polymerase chain reaction (PCR)-GFP analysis further displayed the endophytic nature and early chronological colonisation of the tested EB. This is a preliminary report on root colonisation by a Gram-positive endophyte, B. cereus EB2 and leaf tissues colonisation by both EB isolates as internal colonisers, demonstrating their potential as BCAs to protect oil palm against Ganoderma spp. for a sustainable disease management.

Effect of mixed cropping of water yam (Dioscorea alata) on Ganoderma disease of oil palm

Basal stem rot caused by a soil-borne fungus, Ganoderma boninense, is one of the most severe diseases in monoculture oil palm plantations. The effect of mixed cropping with water yam on infection and inoculum potential of Ganoderma boninense on oil palm seedlings was assessed under a pot experiment. Plant inoculation with rubber woodblock (RWB)-colonized Ganoderma induced disease on both mixed cropped hosts (multiple host infection), but with less severe root necrotic and less plant mortality relative to inoculation on a single oil palm host. Inoculum potential of the pathogen was reduced under mixed cropping, as shown by more considerable RWB decay than a single host, and the fungal survival was suppressed to be 55% for 12 months trial. Water yam mixed cropping did not interfere with the growth of the inoculated oil palm seedling. This study revealed the multiple host infection under mixed cropping with water yam suppressed damage caused by Ganoderma boninense to oil palm as the primary host.

Understanding factors influencing growth and lignocellulosic enzyme of Ganoderma for developing integrated control strategies for basal stem rot disease in oil palm

Understanding factors influencing growth and lignocellulosic enzyme of Ganoderma for developing integrated control strategies for basal stem rot disease in oil palm

Detection and Classification of Basal Stem Rot Disease in Oil Palm Using Machine Learning Techniques: A Mini Review

The oil palm grown around the world to meet the demand for food and bio-fuels, is threatened by a fatal disease known as basal stem rot (BSR). Application of machine learning (ML) in agriculture keeps increasing with the advancement of technology, especially in disease detection. This manuscript presents a mini-review of the different methods relevant to BSR disease classification and detection using ML. The steps were discussed, including pre-processing and approaches used. Various algorithms, feature extractions and classification methods were discussed in the review. The review results revealed that the adoption of disease detection and classification methods for BSR disease in oil palm using ML approaches is still in its early stages of research. Hence, new tools are needed to fully automate the detection and classification processes for practical, operational, fast and accurate systems to be used in vast oil palm plantations.

Trichoderma yunnanense and T. asperellum as potential biological agents for control of basal stem rot disease in oil palm

Basal Stem Rot (BSR) disease is a main constrain in oil palm cultivation. Ganoderma boninense is known as a causal agent of this disease. The intensity of BSR disease continues to increase in both the vegetative and generative phases of oil palm plantations and causes significant losses. Biological control is one of the BSR disease control techniques and is believed to be able to support sustainable oil palm cultivation. Trichoderma spp. is a group of fungal biological agents commonly used to control BSR disease. This study aims to obtain Trichoderma spp. isolates to be developed further as biocontrol agents for BSR disease. The research stages included isolation, morphology-based identification, antagonist potency testing, characterization, and identification with molecular technique. The results in this research obtained one isolate of Trichoderma strain TSU from oil palm plantation at Pematang Siantar Regency, and one isolate of Trichoderma strain TGLP from oil palm plantation at Musi Banyu Asin Regency, which inhibited the growth of G. boninense was 90.9 and 93.9% respectively through dual culture test. Inhibition tests by volatile compounds showed growth inhibition of G. boninense by both isolates were 55.2 and 70.6%. Both Trichoderma strains have the characteristics of producing chitinase, glucanase, and indole acetic acid. Furthermore, molecular identification showed that the Trichoderma strain TSU was similar to the Trichoderma yunnanense strain CBS121219 with an identity percentage of 99.11%, and Trichoderma TGLP as Trichoderma asperellum strain 1A4 with a percent identity of 99.65%. With their antagonistic ability and characteristics, the two Trichoderma spp. isolates have the potential to be further developed as biological agents for controlling BSR caused by G. boninense.

Induced expression of Ganoderma boninense Lanosterol 14α-Demethylase (ERG11) during interaction with oil palm.

The basidiomycete fungus, Ganoderma boninense is the main contributor to oil palm Basal Stem Rot (BSR) in Malaysia and Indonesia. Lanosterol 14α-Demethylase (ERG11) is a key enzyme involved in biosynthesis of ergosterol, which is an important component in the fungal cell membrane. The Azole group fungicides are effective against pathogenic fungi including G. boninense by inhibiting the ERG11 activity. However, the work on molecular characterization of G. boninense ERG11 is still unavailable today. This study aimed to isolate and characterize the full-length cDNA encoding ERG11 from G. boninense. The G. boninense ERG11 gene expression during interaction with oil palm was also studied. A full-length 1860bp cDNA encoding ERG11 was successfully isolated from G. boninense. The G. boninense ERG11 shared 91% similarity to ERG11 from other basidiomycete fungi. The protein structure homology modeling of GbERG11 was analyzed using the SWISS-MODEL workspace. Southern blot and genome data analyses showed that there is only a single copy of ERG11 gene in the G. boninense genome. Based on the in-vitro inoculation study, the ERG11 gene expression in G. boninense has shown almost 2-fold upregulation with the presence of oil palm. This study provided molecular information and characterization study on the G. boninense ERG11 and this knowledge could be used to design effective control measures to tackle the BSR disease of oil palm.

Evaluation and Improvement of Protocols for Ganoderma boninense Protoplast Isolation and Regeneration

Ganoderma boninense is the causal agent of basal stem rot (BSR) disease of oil palm. The BSR disease reduces oil palm yield by up to 80% of the average oil yield. Attempts to control the disease caused by this fungus in the field showed varying levels of success and cases of infection increased from year to year. Hence, the development of new efficient methods to control the spread of this fungus should be commenced promptly. To ensure a better strategy is created, more thorough research on the method deploy by this fungus to infect the host at the molecular level need to be carried out first. However, the major limitation in endeavoring into the functional analysis of virulence genes related to the pathogenicity of this fungus was hampered by the unavailability of established methods for protoplast isolation with a high regeneration rate to be used in the genetic manipulation analysis. Thus, in this paper, we report an efficient protocol for protoplast isolation and regeneration in G. boninense and successfully used the isolated protoplasts in PEG-mediated transformation analysis. A large quantity of protoplast was obtained using the protocol that utilizes the following parameters: 3 to 4-day-old mycelia, treated with 1% lysing enzyme and 0.02% Driselase, incubated at 30 °C in an osmotic medium containing 0.6 M mannitol at pH 5.8 for 2 h. The highest protoplast yield was in the range of 8.95 × 109 to 3.12 × 1010 cells/mL per 5 g of mycelia used. The regeneration rate ranged from 9.03% to 22.55%, depending on the regeneration media used. By using 5 µg of vector to transform into 1.0 × 107 protoplast/mL, around 3 – 10 mitotically stable putative transformants were successfully obtained and verified via PCR. This protocol will find useful applications in genetic studies to enhance insight into this poorly characterized and understood phytopathogen.

1H NMR metabolomics analysis of oil palm stem tissue infected by Ganoderma boninense based on field severity Indices

Basal stem rot disease (BSR) caused by G. boninense affects most oil palm plants in Southeast Asia. This disease can be fatal to palm oil production. BSR shows no signs on the tree in the early stages of infection. Therefore, it is essential to find an approach that can detect BSR disease in oil palm, especially at any level of disease severity in the field. This study aims to identify biomarkers of BSR disease in oil palm stem tissue based on various disease severity indices in the field using 1H NMR-based metabolomics analysis. The crude extract of oil palm stem tissue with four disease severity indices was analyzed by 1H NMR metabolomics. Approximately 90 metabolites from oil palm stem tissue were identified.Twenty of these were identified as metabolites that significantly differentiated the four disease severity indices. These metabolites include the organic acid group, the carbohydrate group, the organoheterocyclic compound group, and the benzoid group. In addition, different tentative biomarkers for different disease severity indices were also identified. These tentative biomarkers consist of groups of organic acids, carbohydrates, organoheterocyclic compounds, nitrogenous organic compounds, and benzene. There are five pathways in oil palm that are potentially affected by BSR disease.

Isolation of actinomycetes from peatland to suppress the growth of Ganoderma boninense the causal agent of basal stem rot disease in oil palm

Abstract. Budi MBS, Giyanto, Tondok ET. 2022. Isolation of actinomycetes from peatland to suppress the growth of Ganoderma boninense the causal agent of basal stem rot disease in oil palm. Biodiversitas 23: 5914-5922. Basal stem rot is a major constrain in oil palm cultivation. The aim of this study was to obtain actinomycetes isolates that can suppress the growth of Ganoderma boninense. The research stages included rejuvenation of actinomycetes isolate stock cultures, observation of morphological characters, analysis of the potency of actinomycetes as biological control agents against G. boninense (antibiosis, volatile organic compound, effect of bioactive compounds in actinomycete culture supernatants and their concentration levels in suppressing G. boninense), physiological characterization and molecular identification was also done of selected actinomycetes. All actinomycetes colonies were grey and brown in color with rectiflexible and vertilicillate spore chain types. Three of the seven isolates tested, namely AKT19, AKT28, and AKT52, were able to suppress the growth of G. boninense up to 100% based on the dual culture test and the percent inhibition of G. boninense growth was 12.27; 17.50; and 23.23% by volatile organic compounds. At 10% concentration, the bioactive compounds of three actinomycetes isolates inhibited the growth of G. boninense, i.e., 89.17, 88.30 and 86.50%, respectively. Further results revealed that isolate AKT19 was the strongest suppressor (70.93) of G. boninense at a concentration of 0.5%, while isolates AKT 28 and 52 inhibited only 15.30 and 4.80%, respectively. All potential actinomycetes isolates produce chitinase, glucanase, cellulase, phosphatase enzymes, fixes nitrogen and secreted indole acetic acid growth hormone. Based on the analysis of 16S rRNA gene, it was noted that all potential isolates were identified as Streptomyces gelaticus.

Identification of Fusarium wilt resistance loci in two major genetic backgrounds for oil palm breeding

Fusarium wilt (FW) caused by Fusarium oxysporum f. sp. elaeidis is the main disease of oil palm in Africa and is a latent threat to other producing regions. A long-term work based on a genetic survey of FW resistance using field observations and pre-nursery screening tests with inoculation resulted in FW resistant planting material whose resistance has not been overcome in 40 years. The genetic determinism of FW resistance has never been studied. Such information would eventually enable marker assisted selection (MAS) to ensure continuous improvement of planting material, through multi-trait selection (yield and disease or multiple diseases) and diversification of the genetic base. In this study, we used a pedigree-based QTL mapping approach that took advantage of the extensive pre-nursery FW resistance data recorded in the framework of a reciprocal recurrent selection program in Benin Republic. Eight QTL regions were mapped in two major genetic backgrounds and favorable QTL alleles were identified in the current breeding populations. The QTL pattern was specific to the population studied in terms of number, location and genetic variance explained, highlighting the different genetic architecture of FW resistance depending on the genetic background. To investigate a putative trade-off between FW resistance and yield, FW resistance QTL genotypes were predicted in a population that was formerly evaluated for yield in the field. The effects on yield of a FW QTL were offset in the commercial planting material thanks to different effects on different yield components in both heterotic groups. These results shed light on FW resistance in oil palm and provide valuable information for the implementation of MAS in the breeding program. Considering that pre-nursery screening tests are widely used, the approach presented here could be implemented in other breeding programs to provide further insights into FW resistance, especially in the context of wider genetic diversity.

Penerapan Metode Forward Chaining Pada Sistem Pakar Identifikasi Penyakit Tanaman Kelapa Sawit

This application of an expert system for identification of oil palm plant diseases aims to make it easier for employees of the Oil Palm Research Center of Sungai Lilin Musi Banyuasin Business Unit to identify oil palm plant diseases based on the symptoms seen then this application provides solutions and appropriate control methods for plant diseases. the oil palm. The data used in this study are data on 10 diseases that exist in oil palm plants and 47 symptoms that appear. The method used in this expert system for identification of oil palm plant diseases uses the Forward Chaining method and the depth-first search tracking technique so that the tracking process will be tested from the first symptom to the last to get a conclusion in the form of the name of the disease along with its causes and how to control it. in this expert system, namely functional testing and expert system testing. Functional testing uses the Black Box method with the Equivalence Patitioning (EP) technique. System testing is carried out by system users, namely. Based on the results of testing with the Black Box method, the developed system functions as expected. Furthermore, expert testing is a test that compares the results of the system diagnosis with the results of expert diagnoses. Expertise test results also show good results. Furthermore, external testing, this test is by giving questionnaires to 35 respondents to get an assessment of the system. The results of the questionnaire (Expert) obtained a satisfaction value of 89.2%Keywords: Oil Palm Disease, Expert System, Forward Chaining Method, depth-first search

Unveiling the Core Effector Proteins of Oil Palm Pathogen Ganoderma boninense via Pan-Secretome Analysis.

Ganoderma boninense is the major causal agent of basal stem rot (BSR) disease in oil palm, causing the progressive rot of the basal part of the stem. Despite its prominence, the key pathogenicity determinants for the aggressive nature of hemibiotrophic infection remain unknown. In this study, genome sequencing and the annotation of G. boninense T10 were carried out using the Illumina sequencing platform, and comparative genome analysis was performed with previously reported G. boninense strains (NJ3 and G3). The pan-secretome of G. boninense was constructed and comprised 937 core orthogroups, 243 accessory orthogroups, and 84 strain-specific orthogroups. In total, 320 core orthogroups were enriched with candidate effector proteins (CEPs) that could be classified as carbohydrate-active enzymes, hydrolases, and non-catalytic proteins. Differential expression analysis revealed an upregulation of five CEP genes that was linked to the suppression of PTI signaling cascade, while the downregulation of four CEP genes was linked to the inhibition of PTI by preventing host defense elicitation. Genome architecture analysis revealed the one-speed architecture of the G. boninense genome and the lack of preferential association of CEP genes to transposable elements. The findings obtained from this study aid in the characterization of pathogenicity determinants and molecular biomarkers of BSR disease.

Implementasi Certainty Factor Untuk Diagnosis Penyakit dan Hama Pada Pelepah dan Daun Kelapa Sawit Beserta Penanganannya

Oil palm (Elaeis guinensis) is a plant that has its own charm and plays an important role in people's lives. Plants are categorized as normal if they can process their physiological functions properly. In line with the development and expansion of community-owned oil palm land areas, more and more problems arise due to various types of diseases and pests attack on oil palm plants, especially on the midrib and leaves of oil palm. The existence of diseases and pests that cause losses in plant productivity also results in loss of costs used to restore plants that have been attacked by diseases or pests in nurseries, immature and mature plants. The lack of understanding of farmers regarding how to diagnose and proper control of oil palm diseases and pests as well as the availability of experts or experts in the field of oil palm in smallholder oil palm plantation areas can be overcome by presenting experts or experts or doubling the knowledge possessed by experts in the coconut field. oil palm by building an expert system for the diagnosis of diseases and pests in oil palm leaf midribs. The certainty factor method is used to describe the uncertainty in thinking and express the degree of confidence of the expert or expert in diagnosing the types of diseases and pests of oil palm. The developed expert system is expected to be useful for farmers in the area or ordinary people in diagnosing diseases and pests on oil palm leaf sheaths through the symptoms selected during consultations to diagnose the types of diseases and pests that are being experienced.

Modeling of oil palm phenology based on remote sensing data: opportunities and challenges

Oil palm phenology has many advantages in managing the sustainability of oil palm plantations. The phenology of oil palms is a key issue in harvest estimation, fruit bunch production, estimating oil palm taxes, replanting, fertilization, and detecting oil palm disease. One of the recently developed methods of oil palm phenology involves the use of remote sensing technology. We evaluated and reviewed the current state of oil palm phenology based on remote sensing and conducted an optimized systematic review of recent scientific publications, specifically focusing on scientific peer-reviewed papers published between 1990 and 2021, comprising over 100 existing journal papers on remote sensing for oil palm phenology. The review includes a description of the state of the art and the mapping of oil palm phenology based on sensors, biophysical tree parameters, and classification techniques and also describes the state of the art in the development of regression models of oil palm phenology based on wavelength, biophysical tree parameters, and the type of regression model. Finally, the review provided an opportunity to develop suitable techniques for the identification, classification, and the construction of regression models of oil palm phenology. There is a lot of potential in combining multisensor approaches, suitable classification methods, and regression models for oil palm phenology. For future studies on oil palm phenology, we recommend integrating machine learning with oil palm biophysical parameters based on multisensor remote sensing technologies.

MOLECULAR PCR ASSAYS FOR DETECTION OF Ganoderma PATHOGENIC TO OIL PALM IN MALAYSIA

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 traditional culture-based assay is time-consuming, labour-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 analysed 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 implementation of effective disease control measures.

Significant Oil Palm Diseases Impeding Global Industry: A Review

Oil palm is the most well-known high yielding and versatile oil crop grown. In 2019, Malaysia ranked as the world's second largest producer of palm oil products (28%) after Indonesia (57%), contributing around USD 9.07 billion to the country’s Gross Domestic Product (GDP) and has been the main economic contributor in the agriculture sector. In recent years, increase in demand has paralleled production. However, pests and diseases have been the major constraints in production causing reduction in palm oil quality and yield. This paper reviews a current status of oil palm diseases of significant economic importance affecting the global oil palm industry. Plant diseases such as basal stem rot (BSR), Fusarium wilt, Phytophthora bud rot, Pestalotiopsis leaf spot, common spear rot, orange spotting and upper stem rot (USR) have been classified as the major diseases of oil palm in terms of economic importance. This paper discusses on the damages caused by the diseases, the causal pathogens and pathogenicity, symptoms as well as treatments or control in the view of developing measures to manage occurrences.

Jengkol Peel Extract (Pithecellobium jiringa (Jack) Prain) as a Biofungicide Against Fungus Curvularia sp., the Cause of Leaf Spot Disease on Oil Palm (Elaeis guineensis Jacq) Seedlings

Leaf spot disease of oil palm caused by fungus Curvularia sp. is a major disease in Oil Palm Seedlings (Elaeis guineensis Jacq). Implementation of best nursery practices is the key to prevent it. This study aims to determine the antifungal activity of Jengkol peel (Pithecellobium jiringa (Jack) Prain) extract against the fungus Curvularia sp. which is the cause of leaf spot disease in oil palm (Elaeis guineensis Jacq) seedlings. This study was carried out for five months at the Plantation Plant Protection Center (Balai Proteksi Tanaman Perkebunan, BPTP) in Pontianak. Jengkol peel extract was screened for its ability to inhibit Curvularia sp. growth by in vitro technique. The research method used a completely randomized design (CRD) with a single factor, namely the concentration of Jengkol peel extract, P0: as a control (without extract), P1: extract with a concentration of 10%, P2: extract with a concentration of 20%, P3: extract with a concentration of 30%, P4: extract with a concentration of 40%, and P5: extract with a concentration of 50%. Parameters observed were suppression of colony diameter and suppression of colony biomass. The results of the study showed that the administration of Jengkol peel extract in P5 treatment (50% extract concentration) had a major effect on suppressing the diameter of fungal colonies (36.44%) and showed a significant difference between each concentration (p < 0.05), while the P3 treatment (30% extract concentration) was able to suppress colony biomass up to 100%. The use of Jengkol peel (Pithecellobium jiringa (Jack) Prain) extract has potential as bio fungicide based on the effect found on the suppression of growth both from the diameter and biomass of the fungal colony of Curvularia sp.

Towards Phytopathogen Diagnostics? Coconut Bud Rot Pathogen Phytophthora palmivora Mycelial Proteome Analysis Informs Genome Annotation.

Planetary agriculture stands to benefit immensely from phytopathogen diagnostics, which would enable early detection of pathogens with harmful effects on crops. For example, Phytophthora palmivora is one of the most destructive phytopathogens affecting many economically important tropical crops such as coconut. P. palmivora causes diseases in over 200 host plants, and notably, the bud rot disease in coconut and oil palm, which is often lethal because it is usually detected at advanced stages of infection. Limited availability of large-scale omics datasets for P. palmivora is an important barrier for progress toward phytopathogen diagnostics. We report here the mycelial proteome of P. palmivora using high-resolution mass spectrometry analysis. We identified 8073 proteins in the mycelium. Gene Ontology-based functional classification of detected proteins revealed 4884, 4981, and 3044 proteins, respectively, with roles in biological processes, molecular functions, and cellular components. Proteins such as P-loop, NTPase, and WD40 domains with key roles in signal transduction pathways were identified. KEGG pathway analysis annotated 2467 proteins to various signaling pathways, such as phosphatidylinositol, Ca2+, and mitogen-activated protein kinase, and autophagy and cell cycle. These molecular substrates might possess vital roles in filamentous growth, sporangia formation, degradation of damaged cellular content, and recycling of nutrients in P. palmivora. This large-scale proteomics data and analyses pave the way for new insights on biology, genome annotation, and vegetative growth of the important plant pathogen P. palmivora. They also can help accelerate research on future phytopathogen diagnostics and preventive interventions.

Defense response changes in roots of oil palm (Elaeis guineensis Jacq.) seedlings after internal symptoms of Ganoderma boninense Pat. infection

BackgroundThe development of basal stem rot (BSR) disease in oil palm is associated with lignin during vegetative growth and salicylic acid (SA) biosynthesis. The increase in the lignin content, SA accumulation, growth, and root biomass could indicate the resistance of oil palm seedlings to BSR disease. Therefore, although there are many studies on the interactions between the Ganoderma boninense and oil palm, research on evaluation of physiological processes, biochemistry, and molecules occurring during early internal symptoms of BSR in roots of oil palm (Elaeis guineensis Jacq.) are essential.ResultsGanoderma boninense inoculation indicated that C01, C02, and C05 seedlings were susceptible, while the other three seedlings, C03, C07, and C08, were resistant based on Ganoderma Disease Index (GDI). Infection by G. boninense in the most susceptible seedlings C05 reduced fresh weight of roots (FW) by 9.0%, and lignin content by 10.9%. The most resistant seedlings C08 were reduced by only 8.4%, and 0.2% regarding their fresh weight and lignin content, respectively. BSR disease induced SA accumulation in the most susceptible C08 and decreased peroxidase (PRX) enzyme (EC 1.11.1.7) activities in root tissues of oil palm seedlings except C07 and C08 where PRX activities remained high in the 4 months after planting. Infection with G. boninense also increased glutathione S-transferase U19-like (EgGSTU19) gene expression in the root tissues of susceptible seedlings, while laccase-24 (EgLCC24) gene expression was associated with resistance against BSR disease. Based on the relative expression of twelve genes, two genes are categorized as receptors (EgWAKL5, EgMIK1), two genes as biosynthesis signal transduction compound (EgOPR5, EgACO1), five genes as defense responses (EgROMT, EgSOT12, EgLCC24, EgGLT3, EgGSTU19), and one gene as trans-resveratrol di-O-methyltransferase-like (EgRNaseIII) predicted related to BSR infection. While two other genes remain unknown (EgUnk1, EgUnk2).ConclusionsGanoderma infection-induced SA accumulation and lignification in resistant accessions promote the seedlings root biomass. Oil palm seedlings have a synergistic physical, biochemical, and molecular defense mechanism to the BSR disease. The utilization of nucleotide-based molecular markers using EgLCC24 gene is able to detect resistant oil palm seedlings to G. boninense.