Papers by arnnyitte alexander
SpringerBriefs in Agriculture, 2017
Basal Stem Rot (BSR) disease has been spreading fast due to the inability to detect infection at ... more Basal Stem Rot (BSR) disease has been spreading fast due to the inability to detect infection at the early stage in the field. The detection of the disease is challenging because the external symptoms are only visible when it is at the critical stage. During this stage, any treatment or management methods are no longer effective. Therefore, many viable and effective methods to detect the presence of G. boninense has been developed to diagnose the disease at early stage. This chapter elaborates established methods in detecting G. boninense including molecular analysis, biochemical assay, field detection methods using devices and some others emerging methods currently utilized.
Universiti Malaysia Sabah, 2014
EFFICACY OF MICROBIAL APPROACHES IN CONTROLUNG Ganoderma boninense Pat AND THEIR EFFECTS TO SOIL ... more EFFICACY OF MICROBIAL APPROACHES IN CONTROLUNG Ganoderma boninense Pat AND THEIR EFFECTS TO SOIL MICROBIAL DIVERSITY Basal Stem Rot (BSR) is the most destructive disease of oil palm (El aeis guineensis Jacq.) which caused by bracket fungus; Ganoderma boninense. With no remedy to date, this disease has jeopardized the industry of oil palm critically. Several approaches including cultural, chemical, mechanical and biological measures have been reported in attempt to control this disease, but unfortunately, none have given satisfactory result. Therefore, a more reliable approach that could manage this disease, besides a continuous and sustainable oil palm production is worth to be further investigated. Introduction of microbes in disease management have been used for decades. An astute observation of low incidence of disease due to Ganoderma pathogen in natural ecosystem suggests that a healthy natural ecosystem can hinder the incidence of Ganoderma pathogen outbreak. In this respect, study on the potential of microbes in suppressing the growth of Ganoderma boninense and its effect to the soil microbial diversity were investigated in this project. Three microbes-based products which are Living Soil Microbes (LSM), Agrinos (AGN) and Agriorganica (AO) were tested in this study. LSM contains multi-strain of Bacillus spp. and Trichoderma spp., whereas AGN consist of Bacillus spp., Pseudomonas spp. and Aspergillus sp. Meanwhile, AO comprises of three living food microbes which are Lactobacillus, Nattobacillus and Saccharomyces cerevisiae developed from Japanese fermentation and brewing technology. To examine the ability of the treatments in reducing BSR disease incidence, assessments in nursery and field trial were conducted. The results from both trials showed that LSM, AGN and AO were able to reduce the colonization of G. boninense based on the reduction of ergosterol content compared to untreated control. Based on the nursery results in prevention of Ganoderma colonization trial, after two months interval, LSM and AO showed greater reduction of ergosterol content with 1.991 µg g-1 and 1.994 µg g-1 respectively, however LSM recorded the lowest Disease Incidence (DI) with only 30%. After four months interval, LSM and AGN showed greater reduction in ergosterol content with 2.261 µg g-1 and 2.214 µg g-1 respectively, however, AGN and AO had the lower DI with 60%. Meanwhile, based on the results In suppression of Ganoderma colonization trial, after two months of interval, all treatments successfully reduced the ergosterol content and DI within the time frame. After four months interval, all treatments showed an increment in DI, however,
SpringerBriefs in Agriculture, 2017
The oil palm industry is under threat of a prevailing incurable disease called Basal Root Stem (B... more The oil palm industry is under threat of a prevailing incurable disease called Basal Root Stem (BSR), which is caused by a white rot fungi, known as Ganoderma boninense . With no current remedy at present, BSR is the major disease in oil palm plantations of SEA and, therefore, of great economic importance to the world oil palm industry, especially to Malaysia and Indonesia, which are oil palm major producers and exporters. The disease is highly associated with the decay of lower stem, leading to severe symptoms such as unopened and flattening spear leaves. There are numerous mode of infection associated with the epidemiology of G. boninense in oil palm plantation, including in-contact roots with nearby diseased palms and through airborne basidiospores . Deep insight on the route of infection and mycological pathogenicity behaviour of the pathogen is the greatest priority in order to successfully develop effective management practices for disease control.
SpringerBriefs in Agriculture, 2017
Basal Stem Rot (BSR) is a very important disease to the oil palm industry. When it was first reco... more Basal Stem Rot (BSR) is a very important disease to the oil palm industry. When it was first recorded, BSR only affected mature palms. However after years, the disease had progressed to affecting younger palms and causing more losses. The disease continues to inflict considerable yield losses of infected palms and also direct loss of stand due to palm death. Attempts to control the disease has been taken to wider extent, including cultural practices (clean clearing, windrowing, mounding, surgery, digging trenches, sanitation), fungicide application, development of resistance variety and application of biological control agents. This chapter elaborates all possible managing strategies in combating Ganoderma boninense. 4.1 Cultural Practices Good cultural practices are often advisable in the management of BSR in established oil palm plantations. Cultural measures usually involve eradicating and reducing the pathogen inoculums to avoid disease spread. These include clean clearing, windrowing, soil mounding, surgery, digging trenches and sanitation. 4.1.1 Clean Clearing Clean clearing is a procedure of excision and removal of all remaining fragments within an infected palm area by digging pits with 1.5 m 2 and 60 cm deep from both untreated vacant points and diseases palm points (Singh 1990; Flood et al. 2000). Generally, all remaining fragments from the infected palm will be brought to the surface for subsequent removal or burned down. However, this method is costly, and open burning is forbidden in many palm oil producing countries and in Malaysia it is governed under Air Regulation Act of 1978. Therefore, a common practice is to shred all palm fragments and can either be scattered over the whole field or stacked in rows and covered with legume cover crop to facilitate decay.
ASM Science Journal, 2021
Understanding oil palm’s cell wall lipid during pathogenic invasion, especially from Ganoderma fu... more Understanding oil palm’s cell wall lipid during pathogenic invasion, especially from Ganoderma fungus helps us to devise better strategies in managing Basal Stem Rot caused by the fungus effectively. However, as the lipids of plant’s cell wall is a delicate subject, while acquiring them in ample amount with decent quality for research purpose is an excruciating work, therefore it is crucial to develops an optimised method for acquisition. In this study, the effects of solvent ratio, extraction time, extraction temperature and biomass to solvent ratio pertaining effective lipids extraction from oil palm roots cell wall were investigated, aided with Central Composite design (CCD) of Response Surface Methodology (RSM) analysis to obtain optimum oil palm cell wall lipid extraction conditions. Using the projection of RSM model and validation of empirical evaluation, the results revealed that the optimum cell wall lipids yield was obtained under the following extraction conditions: 10 mL ...
The ability of potential antagonists, a commercial product containing combinations of microorgani... more The ability of potential antagonists, a commercial product containing combinations of microorganisms (TR1) to control Ganoderma boninense growth was investigated in this research. TR1 contained multiple strains of Bacillus spp. and Trichoderma spp. The results from field experiments showed that TR1 was all able to reduce the colonization of G. boninense, based on re-isolation of the pathogen onto a selective medium and the reduction of ergosterol content compared to untreated controls. Effectiveness of TR1 was therefore further investigated for mode of action studies. Scanning Electron Microscopy (SEM) observations of Ganoderma mycelium, recovered from bioassay plates on which TR1 had inhibited fungal growth, showed that the mycelium was highly disrupted and lysed after exposure to the treatment. The production of potentially antifungal components produced by TR1 microbes in broth cultures was further investigated using Liquid Chromatography Mass Spectrometry (LCMS). Several antimic...
Optimal yield production of oil palm in Malaysia and other countries of South East Asia are hampe... more Optimal yield production of oil palm in Malaysia and other countries of South East Asia are hampered by the presence of devastating Basal Stem Rot (BSR) disease caused by Ganoderma boninense. For more than 40 years, Ganoderma remained to be the most serious problem in many areas in Malaysia and Indonesia. But unfortunately, there is no single reliable application in suppressing or controlling either the disease severity or a promising resistant variety of oil palm to this pathogen. AVROS is the most commonly planted oil palm variety in Sabah derived from the Dura x Psifera (D x P) and claimed to be more resistant to G. boninense in comparison to other commercial varieties. In this paper the susceptibility of AVROS to G. boninense is compared to two other varieties; Calabar and Ekona which have the same Dura but with African origin Psifera. In general, the accumulation of the ergosterol, a specific indicator associated with fungi, increased significantly throughout the study in all the three varieties indicating increasing of infection. Varieties of Ekona and Calabar were found to be more susceptible to G. boninense based on the higher content of ergosterol found in root compared to AVROS at week four, five and six. The ergosterol results are also supported by the disease severity score as described by Horsfall and Barratt, 1945 which shown Calabar and Ekona scored higher than AVROS in the infection.
Transactions on Science and Technology, 2016
Basal Stem Rot (BSR) disease caused by Ganoderma spp. is the most devastating disease of oil palm... more Basal Stem Rot (BSR) disease caused by Ganoderma spp. is the most devastating disease of oil palm in Southeast Asia. This paper discusses sustainable approaches in managing BSR disease particularly on early detection and control of Ganoderma with some examples from oil palm estates in Sabah. New detection methods such as ergosterol analysis and Ganoderma signature via Fourier Transform Infrared Spectroscopy (FTIR) are emphasized. Latest disease control methods with great potentials such as combination of biological control agents (BCAs), enhancing defense mechanism of oil palm through enviro-friendly approach, potential biomarkers for selection of resistant breeding materials and utilization of eco-friendly fungicide were also discussed.
The effects of different basal media and complex additives on in vitro seed germination of Coelog... more The effects of different basal media and complex additives on in vitro seed germination of Coelogyne asperata were studied. Seeds of C. asperata after 182 days of pollination were cultured on three basal media of Knudson C (KC), Vacin and Went (VW), and Murashige and Skoog (MS) and maintained at 25±2°C under 24h light. After 40 days of culture (OAC), seeds were germinated on KC, MS and WI media at 96.45±2.68%, 95.51±3.01 % and 97.22±1.99% with growth Index (GI) valued 387.04, 375.24 and 379.79 respectively. The effect of complex additives was studied by using KC as basal medium, added with different types of complex additives such as 10% (v/v) of coconut water (CW), 10% (w/v) of potato homogenate (POT and 10% (w/v) of tomato juice (TJ). After 70 DAC, the germination percentage on KC (control), KC + 10% (v/v) CW, KC + 10% (w/v) POT and KC + 10% (w/v) TJ showed responsive germination percentage with GI value at 416.57, 375.4, 387.3 and 354.2 respectively. The finding concluded th...
Available control measures in managing Basal Stem Rot (BSR) disease has given unsatisfactory resu... more Available control measures in managing Basal Stem Rot (BSR) disease has given unsatisfactory result. Alternative control measure to overcome this disease are now focused on the use of Biological Control Agents (BCAs) . Currently introduction of Multiple Biological Agents (Multi-BCAs) to expand their mode of action has been applied in managing plant pathogen. Selecting the right combination of antagonists is necessary not only to avoid competition among the BCAs but also complementing each other. In addition, a different ecological requirement of BCAs would broaden the range of environmental conditions and made the biological control more feasible. Most combinations are only involving two organisms, but few involved combinations of three or more organisms. In this chapter, the efficacy of microbes using combinations of microbes which are solely Multi-BCAs and Multi-BCAs with additive against Ganoderma boninense are discussed.
A protocol for in vitro seed germination of Coelogyne asperata Lindl. has been established succes... more A protocol for in vitro seed germination of Coelogyne asperata Lindl. has been established successfully. Immature seeds from 182 days old capsule were cultured on three different basal media; Murashige and Skoog (MS), Knudson C (KC), and Vacin and Went (VW) and maintained under continuous light at 25 ± 2 ̊C. After 30 days of culture (DAC), more than 90% of seeds were germinated on KC and VW media and about 84% of seeds germinated on MS medium. The incorporation of organic additives, including coconut water, potato homogenate and tomato juice each at 10% (v/v) in KC medium was tested to determine their effect on seed germination of C. asperata. The result revealed that KC basal medium alone without addition of organic additives promoted over 90% of seed germination at 30 DAC. Therefore, the protocol of using standard KC basal medium for C. asperata seeds germination could be suggested for mass propagation and conservation of this wild scented orchid.
JOURNAL OF SUSTAINABILITY SCIENCE AND MANAGEMENT, 2021
This study aims to investigate the combination of biological control agents in managing Ganoderma... more This study aims to investigate the combination of biological control agents in managing Ganoderma boninense, the causal pathogen of Basal Stem Rot (BSR) disease in oil palm. The effectiveness of biological control agents (BCA) namely T1, T2 and T3 in managing BSR disease was tested and evaluated in the nursery and the field. Assessment on the disease progression of artificial Ganoderma inoculated oil palm seedlings based on disease severity (DSI) and bole severity index (BSI) was observed and recorded. The percentage of disease incidence (DI) was calculated for each treatment. Root and trunk tissue samples of the treated oil palms were collected and analyzed for their ergosterol content using High Performance Liquid Chromatography (HPLC) and plated on GSM. The findings showed BCA-based products are unable to prevent BSR infection in nursery trials. Nonetheless, if ergosterol content is taken as a representative of Ganoderma biomass in the oil palm tissue, the progression of the pathogen has been disrupted by the BCA. A longer observation period and additional parameters shall be taken in future studies to further validate the potential of these BCA.
International Journal of Advances in Agricultural and Environmental Engineering, 2014
Ganoderma boninense is a basidiomycetes fungus that causes basal stem rot disease (BSR) in oil pa... more Ganoderma boninense is a basidiomycetes fungus that causes basal stem rot disease (BSR) in oil palm trees. In Malaysia alone, the loss caused by this disease was estimated between RM 225 Million to RM 1.5 Billion in 2011 by Malaysian Palm Oil Board. Unfortunately, many planters do not realize that their fields were infected with BSR until it is too late. Several methods have been proposed for early detection of Ganoderma boninense infection. In this paper, Fourier transform infrared spectroscopy (FTIR) is investigated as a tool to detect the presence of Ganoderma boninense in oil palm tree. It is shown that there are differences in the FTIR result from the infected and healthy oil palm tree that resembles the FTIR characteristics from pure Ganoderma boninense. The result presented in this paper shows the possibility of FTIR as a tool for detecting the infection of the fungi in oil palm tree.
IOP Conference Series: Earth and Environmental Science, 2017
Bangladesh Journal of Pharmacology
Journal of Oil Palm Research
Oil palm (Elaeis guineensis Jacq.) is an oil crop widely cultivated throughout Southeast Asia cou... more Oil palm (Elaeis guineensis Jacq.) is an oil crop widely cultivated throughout Southeast Asia countries. Unfortunately, the industry is badly affected by Basal Stem Rot (BSR) disease, caused by soil-borne pathogen, Ganoderma boninense, which is the most devastating and widespread disease in oil palm. Although some investigations have been conducted, complete understanding on BSR infection is yet to be achieved. In this article, observation on roots of inoculated oil palm seedlings under scanning electron microscopy showed G. boninense colonisation predominantly formed on root surface, proving endophytic colonisation primarily through the hair base, crossing epidermal cells, and followed by spreading into cortical cells which a possible pathway leading to vascular system. It also showed the formation of highly dense hypal network within the colonised area, mainly in the epidermal and cortical cells. By six months of inoculation, cell compartment of infected roots was lost and noticeable changes in the root cells structure were observed. The present study provides additional insights in the infection process and pathogen route inside the host tissue and may be useful for development of disease control strategies.
American Eurasian Journal of Sustainable Agriculture, 2014
ABSTRACT Soil microbial community plays an important role in the soil ecosystem and the diversity... more ABSTRACT Soil microbial community plays an important role in the soil ecosystem and the diversity of microbial community may act in check and balance to various plant pathogens. However, soils microbes are very sensitive to changes in soil condition. The use of Biological Control Agents (BCAs) is regarded as a promising measure to control Basal Stem Rot (BSR) of oil palm disease. However, its potential effect on other soil microbes is not clear. This paper reports the impact application of two BCAs-based products in the soil microbial population and diversity on oil palm plantation soil. Isolation of microbes from the soil was carried out using plate counts techniques on various media such as Potato Dextrose Agar (PDA), Malt Extract Agar (MEA) and Nutrient Agar (NA). The presence of viable microbes on cultured media was observed and counted using Colony Forming Unit (CFU) method and later identified using Biolog and molecular techniques. The CFU for bacteria and yeast after application of these microbial treatments were remains unchanged, which varied between 10 3 to 10 6 cfu/g and 10 2 to 10 6 cfu/g of soil respectively. However, CFU for fungi has increased to 10 4 cfu/g of soil. Identification based on Biolog and molecular technique shows that new species arose and overcome the predominated species after application of these microbial products. The new identified species were Enterobacter spp., Microbacterium spp., Burkholderia spp., Yarrowia spp., Streptomyces spp., Trichoderma spp., etc. Application of BCAs to soil could possibly enhance the richness and evenness of microbial distribution in soil.
Asia Pacific Journal of Molecular Biology and Biotechnology, Dec 1, 2012
This book is a simplified manual for Ganoderma detection in field. It consists chapters on biolog... more This book is a simplified manual for Ganoderma detection in field. It consists chapters on biology and epidemiology of Ganoderma, ergosterol as a fungal biomarker essential steps in TLC detection method including oil palm tissue collection to preparation of tissue for the analysis. This book is a reference for planters, plantation personnel and researchers for Ganoderma detection on their own.
Uploads
Papers by arnnyitte alexander