Category Archives: 2018 Vol 30 March

BREEDING FOR DROUGHT TOLERANCE IN OIL PALM

As the oil palm industry expands, drought tolerance will become increasingly important. In the breeding programme of Univanich Palm Oil PCL in Southern Thailand, progeny trials are duplicated with and without irrigation. This allows drought tolerance of progenies to be estimated, in terms of the reduction in yield caused by withholding irrigation. Correlations between irrigated and unirrigated progeny mean yields are low, and some pairs of trials show significant progeny x irrigation interactions. Unirrigated yield is highly correlated with drought tolerance, but yield under irrigation tends to be negatively correlated with tolerance. Thus, selection in the absence of drought may produce material that is drought susceptible, and selection should be done under the conditions in which the material will be planted. We have not found a reliable indirect method for identifying drought tolerance, but the use of stomatal conductance as a selection criterion appears worth investigating further.

VALIDATION OF DIFFERENTIAL GENE EXPRESSION OF TRANSCRIPTOME ASSEMBLY VIA NANOSTRING® TECHNOLOGIES ANALYSIS PLATFORM

Ganoderma boninense is a white rot fungus that causes basal stem rot (BSR) disease that contributes to profit loss in the oil palm industry. Transcriptome profiling using RNA-sequencing (RNA-seq) approach had been conducted to discover the differential express transcripts which relate to BSR disease that might potentially be utilised as biomarker for selection of Ganoderma tolerant oil palm. To validate the expression of transcripts in medium throughput manner after large scale transcriptome profile, new approaches are available such as reverse transcription quantitative PCR (RT-qPCR) of Fluidigm’s BioMark HD system that runs on microfluidic chips, and NanoString’s nCounter system that gives absolute counts of the mRNA itself without involving cDNA synthesis and PCR amplification. In this study, differential express transcripts were identified from the comparative transcriptomic of the transcriptome of near-rot section of basal stem tissue of oil palm infected with G. boninense against healthy non-infected palms. Then, whether the transcript abundances measured using RNA-seq method was correlated with the nCounter system for the selected transcripts was assessed. Based on the selected 24 transcripts, transcript abundances measured was significantly correlated between RNA-seq and nCounter system (p < 0.001). Out of 24 assessed transcripts, three transcripts were highly similar in the measured expression profiles using both platforms. From the three transcripts, only two showed potential as biomarkers for detecting G. boninense tolerant trait in oil palm.

COMPUTATIONAL IDENTIFICATION OF MICRORNA IN FIVE WOODY OIL TREE CROPS AND THEIR miRNA TARGET SEQUENCES

Recently discovered miRNA (microribonucleic acids) are a kind of endogenous small RNA that have important regulatory roles during eukaryote development and stress responses by controlling mRNA
degradation or inhibiting translation. However, little is known about miRNA from commercially important woody oil crops. Using a comparative genomics approach and following a series of stringent filtering criteria, we identified 36 woody oil crop miRNA belonging to 22 families using expressed sequence tags and genome survey sequence databases. The numbers of miRNA found in walnut (Juglans regia), oil palm (Elaeis guineensis), tea (Camellia sinensis), tung oil tree (Vernicia fordii) and barbados nut (Jatropha curcas) were 17, 11, 3, 3 and 2, respectively. In addition, 275 potential target genes were predicted for 27 newly identified miRNA utilising mRNA databases of J. curcas, E. guineensis, C. sinensis, J. regia, V. fordii and Olea europaea plant species. Most of the target mRNA encoded transcription factors that regulated plant growth and development, together with a few target genes that were involved in metabolism or stress responses. Sequence alignments of 10 miRNA families from different species showed that miRNA sequences within the same family were variable. Furthermore, the authenticity of 11 novel miRNA candidates from oil palm was verified by semi-quantitative and quantitative reverse transcription-polymerase chain reaction (RT-PCR). A correlation analysis revealed a close correlation between the two PCR assay methods. The expression levels of miRNA transcripts significantly differed between the leaf and the fruit tissues of E. guineensis.

ASSOCIATION OF SNP MARKERS WITH HEIGHT INCREMENT IN MPOB-ANGOLAN NATURAL OIL PALM POPULATIONS

Low height increment is one of the desired traits in oil palm breeding and improvement programmes, as dwarf palms facilitate fruit harvesting and extend the economic life of the crop. In this study, 346 natural oil palms collected from Angola and maintained by the Malaysian Palm Oil Board (MPOB) were used. Analysis of variance (ANOVA) for height increment showed a significant difference (P ≤ 0.001) among families in populations, indicating substantial genetic variation for marker-trait association study. We applied nine carefully selected single nucleotide polymorphism (SNP) markers to genotype the oil palms via cleaved amplified polymorphic sequence (CAPS) method. Population structure analysis involving 18 SNP alleles divided the palms into two sub-populations, with no obvious relative kinship (values < 0.3). For association analysis between the SNP markers and height increment, three models were tested. The incorporation of population structure (Q) and relative kinship (K) as correction factors in the model had helped reduce false positive associations. Generally, the mixed linear model (MLM) with Q + K exhibited a more stringent model with less spurious associations detected. Based on this model, one significant marker SNPG00006_FatI corresponding to indole-3-acetic acid (IAA)-amido synthetase gene was identified to be associated with height increment (P ≤ 0.05). The marker, although potentially specific to MPOB-Angolan germplasm, can assist in introgressing the dwarf phenotype into advanced breeding materials through marker-assisted selection (MAS).

LONG-TERM STUDY OF Bacillus thuringiensis APPLICATION TO CONTROL Tirathaba rufivena, ALONG WITH THE IMPACT TO Elaeidobius kamerunicus, INSECT BIODIVERSITY AND OIL PALM PRODUCTIVITY

A long-term study of commonly used insecticides for Tirathaba rufivena control was conducted in Riau, Indonesia. Treatments included fipronil, Bacillus thuringiensis subsp. kurstaki (Btk), and a rotation of Rynaxypyr and Btk applied every two weeks for a nine-month period. Assessments were monitoring of T. rufivena attack, quantifying the number and activity of E. kamerunicus, insect biodiversity, and analysis of oil palm fruit set and productivity. Despite overlapping pest stages, all insecticides were effective in reducing Tirathaba larvae within four months for Btk-containing treatments and two months for fipronil, while Tirathaba attack in the untreated control initially increased and then remained persistently high. Fipronil reduced the numbers of E. kamerunicus weevils visiting inflorescences one month after application while Btk-containing treatments did not reduce weevil populations resulting in <70% and >75% fruit set, respectively. Average bunch weight in treatments, which included Btk, was 11.7% higher than the fipronil treated blocks and 64.5% higher than the control block resulting in a yield increase of 14.4% and 55.5% over fipronil treatments and controls, respectively. Btk treatments were effective in controlling Tirathaba, did not impact E. kamerunicus or overall insect biodiversity and positively impacted oil palm fruit set, bunch weight and productivity.

PROFILING OF ANTI-FUNGAL ACTIVITY OF Trichoderma virens 159C INVOLVED IN BIOCONTROL ASSAY OF Ganoderma boninense

Trichoderma has long been recognised as a potential biological control agent (BCA) against pathogenic fungi due to antagonistic characteristics and it has successfully controlled Ganoderma boninense at the nursery stage in previous study. This study attempts to identify the mechanisms involved in the suppression of G. boninense and the anti-fungal compounds released by endophytic Trichoderma virens 159c. Therefore, culture filtrates of endophytic T. virens 159c was extracted using hexane, ethyl acetate (EtOAc) and butanol (BuOH) and anti-fungal activity was tested. The EtOAc extract showed highest anti-fungal activity with percentage inhibition of radial growth (PIRG) of 78.39% ±5.40. The scanning electron microscope (SEM) showed severe deformation of G. boninense PER 71 mycelia observed at the inhibition region caused by EtOAc extract. Further fractionated with column chromatography and antifungal assay revealed that fractions 2 and 4 had highest anti-fungal activity. Analysis carried out using gas chromatography-mass spectrometry detector of the active fraction allowed the identification of acetamide, alcohol, lactones and free fatty acids. Phenylethyl alcohol (PEA) was discovered as a unique compound because the presence was only in the highly inhibitory fraction of T. virens. In addition, dl-mevalonic acid lactone in fraction 4 of T. virens 159c was first reported in T. virens.

INFLUENCE OF EDDY COVARIANCE SENSOR HEIGHT ABOVE THE OIL PALM CANOPY ON CO2 AND ENERGY FLUXES

A study was carried out to determine the influence of eddy covariance (EC) sensor placement above the oil palm canopy on footprint, CO2, and energy fluxes. The study was carried out on 18-year old oil palms planted on mineral soil at an inland location in Peninsular Malaysia. Measurements were done from July to September 2016. The open path CO2/H2O analyser and 3-D sonic anemometer were initially installed at 30 m height. Both sensors were later repositioned at 19 m height on 2 August 2016. The different sensor heights had a significant effect on the diurnal CO2 fluxes above the oil palm canopy. The average CO2 flux measured was about -3.77 μmol CO2 m-2 s-1 at 30 m and was reduced to -0.75 μmol CO2 m-2 s-1 at 19 m height. Lowering the sensor height also reduced the CO2 flux footprint by about 40% to a distance of 584 m. The energy imbalance is evident at the two different sensor heights and needs to be further studied.

DEVELOPMENT AND FIELD EVALUATION OF A TRACTOR MOUNTED OIL PALM TRUNK INJECTOR

This article describes the design, development and testing of a trunk injection machine. The machine comprised of an injection apparatus, hydraulic system and 200-litre storage tank mounted on a mini-tractor. Experiments were conducted to test injection effectiveness test, time and motion study (TMS) and field trial. The injection effectiveness test using 0.1% eosin dye on the healthy palms revealed that the machine was able to spread the dye to more than 60% coverage on the vertical (X) and horizontal (Y) axes, and up to 65 cm upwards on the longitudinal axis (Z). Results recommended to have two injections per palm for a better coverage profile. TMS revealed that the machine was able to treat about 37 palms per day with the injection cost of about RM 3.15 per palm. Study on 2088 Ganoderma-infected palms in an estate showed that 95.6% of the infected palms were still standing after one year treatment with Hexaconazole. The cost-effectiveness was calculated at RM 1.02 per palm over five-year of economic life. With the performance and cost of the machine, it is recommended that this machine is suitable to be used to treat palms infected with basal stem rot disease (BSR).

METABOLITE PROFILING OF CORE OIL PALM TRUNK (COPT) SAP: THE EFFECTS OF DIFFERENT STORAGE DURATIONS, CONDITIONS AND TEMPERATURES

In Malaysia, core oil palm trunk (COPT) is one of the biomass that has been left underutilised due to its low properties. Nonetheless, metabolites contained in COPT sap may provide an alternative natural resources for bio-chemicals and pharmaceuticals. Metabolites such as sugars are easily affected by analytical factors during storage. In this study, the changes of metabolite contents in COPT sap stored at different storage durations, conditions and temperatures were observed by using gas chromatography-mass spectrometry (GC-MS) based metabolomics approach. The changes of metabolite contents, particularly sugars and organic acids were analysed using univariate and multivariate statistical analysis. The separation trends observed in the principal component analysis (PCA) score plot was greatly influenced by storage temperatures. However, two-way analysis of variance (ANOVA) revealed that the majority of significant metabolites (P<0.05) was strongly influenced by storage durations. The metabolite increased significantly when COPT was stored as raw rather than sap. The highest sugar concentrations in COPT were found at 10°C for one month (R-10-1M). Furthermore, the organic acids increased significantly when stored at 4°C for one month (R-4-1M). The results indicated different storage durations, conditions and temperatures led to variation in the COPT sap metabolite content.

CONVERSION OF PRE-TREATED OIL PALM EMPTY FRUIT BUNCHES INTO BIO-OIL AND BIO-CHAR VIA FAST PYROLYSIS

The empty fruit bunch (EFB) is a cumbersome biomass generated during the palm oil milling process. It is one of the most extensively researched biomass. This is due to its abundant availability from the palm oil industry – spread over Malaysia, Indonesia and to some extent Thailand. It is widely recognised as a potential fuel but its use faces much hurdle, mainly due to its high ash content. Converting EFB into valuable fuel resources such as bio-oil and bio-char, through the pyrolysis process, would be beneficial not only to support national energy security but also economic growth. In this study, the thermal conversion of the unwashed and washed EFB through fast pyrolysis was carried out using a fluidised bed reactor at 500°C with particle sizes ranging from <90 μm to 180 μm. Three types of pre-treatment were performed. These were washing with H2SO4 (0.1 M), NaOH (0.1 M), and distilled water. The aims were to investigate the impact of the different washings on the resulting pyrolysis products and the corresponding ash effects. The results indicated that the EFB washed with H2SO4, which gave the highest reduction in ash content i.e. ~56%, gave the maximum bio-oil yield (55.6 wt.%) while that washed using NaOH with ~50% ash increment produced the highest amount of bio-char (36.9 wt.%) and gas (38.8 wt.%). The resulting bio-oil and bio-char from the washed feedstock with much reduced ash had similar fuel characteristics with those from the unwashed feedstock, with the latter a better fuel in terms of calorific value, i.e. 19 -23 MJ kg-1 vs. 20-25 MJ kg-1, respectively.

BIO-CHAR AND BIO-OIL MIXTURE DERIVED FROM THE PYROLYSIS OF MESOCARP FIBRE FOR BRIQUETTES PRODUCTION

A huge amount of mesocarp fibre (MF) is generated as wastes in Malaysia. These wastes will continue to pose disposal problems in Malaysia, unless effectively deployed. This research aims to produce charcoal briquettes from the pyrolysis products of such wastes (bio-char and bio-oil). The MF was pyrolysed at a temperature of 400°C, a heating rate of 10°C min-1 for 1 hr. Sago starch was added to improve the bio-oil viscosity. Bio-char and bio-oil binder were mixed respectively in the ratio of 70:30 for the charcoal briquettes production. Bio-oil viscosity was improved to 49.6 cP from 1.9 cP. Consequently, higher heating value (HHV), pH value and density of bio-oil were increased to 21.23 MJ kg-1 from 17.06 MJ kg-1, 4.76 from 3.14 and 1529 kg m-3 from 1337 kg m-3, respectively. The physio-chemical properties and the durability of the briquettes were analysed and compared to briquettes obtained with sago starch binder. The results have revealed that briquettes made with bio-oil binder had high HHV of 29.1 MJ kg-1, density, and water resistance. The briquettes made with sago binder were more durable. This study could boost the application of pyrolysis products, especially bio-oil which has some disadvantages as fuel. It can reduce the dependence on fossil fuels such as coal in some applications.

PALM OIL MILL EFFLUENT AS ALGAE CULTIVATION MEDIUM FOR BIODIESEL PRODUCTION

Palm oil mill effluent (POME) – a wastewater from the palm oil milling process is beneficial as a low cost carbon source for microalgae growth. This does not only help clean the wastewater but also reduce the algal cultivation cost. In this study, the growth rate, biomass productivity and biochemical compositions of Chlorella sp. grown in diluted POME under outdoor conditions using a 200-ml capacity high rate alga pond (HRAP) and two closed photobioreactors (PBR) i.e. annular and flat panel were assessed. The strain, Chlorella sp. grown on 5% of POME in a flat panel PBR exhibited the highest specific growth rate of 0.5 per day and biomass productivity (137.5 mg litre-1 per day) followed by those in HRAP and annular PBR. Additionally, a good growth of Chlorella sp. in POME could sufficiently utilise the nutrients of POME such as phosphate (PO4), nitrate (NO3), nitrite (NO2) and organic substances. The extracted algal oil from the diluted POME culture (5%) showed decrease in the saturated fatty acids and an increase in the polyunsaturated fatty acids compared to those cultured in the standard Bold’s Basal Medium (BBM). The biochemical compositions of the algae grown in the flat panel PBR were the highest with lipid, protein and carbohydrate productivity of 17.9 mg litre-1 per day, 34.7 mg litre-1 per day and 21.4 mg litre-1 per day, respectively. The microalgae cultivation in diluted POME had not only shown good potential as a biodiesel feedstock based on the fatty acids profile but also the ability to reduce some pollutants e.g. PO4, NO3, NO2 and chemical oxygen demand (COD) in the biological wastewater treatment.

In vitro SAFETY EVALUATION OF PALM TOCOTRIENOL-RICH FRACTION NANOEMULSION FOR TOPICAL APPLICATION

The application of nanotechnologies in cosmetics industry has resulted in the introduction of new nanomaterials for topical applications. Nanomaterial overcomes issues of limited penetration and low bioavailability of non-soluble bioactive agents. While there are many advantages of using nanomaterials, recent development in using submicron particles for enhance skin penetration has raised the concern of safety including the increase potential to induce skin irritation and allergic reactions on the skin. The studies on irritation potential of palm tocotrienol-rich fraction (TRF) nanoemulsion using in vitro ocular and dermal irritection assays, reconstructed human epidermis and human corneal epithelium tests were investigated. Palm TRF nanoemulsion did not exhibit any potential skin irritation in the in vitro ocular and dermal irritation assessment. The studies showed that when reconstructed human corneal epithelium and human epidermis models were treated with the tocotrienol macroemulsion and nanoemulsions, no indication of irritancy to the eyes or dermal tissues were observed giving a mean tissue viability of more than 60% and 50%, respectively. The non-irritant category is classified as Category 1 according to United Nations Globally Harmonised System of Classification and Labelling of Chemicals. In vitro studies showed no ocular or dermal irritation potential indicating possible topical application of palm TRF nanoemulsion.

MALAYSIA: 100 YEARS OF RESILIENT PALM OIL ECONOMIC PERFORMANCE – Review Article

The oil palm industry in Malaysia started about 100 years ago in a modest way. It was first introduced to Malaya (now Malaysia) as a commercial plant in 1917 at the Tennamaram Estate in Selangor, which effectively laid the foundation for the development of the oil palm industry in Malaysia. The oil palm planted area had expanded phenomenally from a mere 55 000 ha in 1960, to 5.74 million hectares in 2016. In tandem with the area expansion, the production of palm oil also grew significantly from less than 100 000 t in 1960 to about 17.32 million tonnes in 2016. From a humble beginning in 1960, the Malaysian oil palm industry has transformed to become one of the key contributors to the Malaysia’s Gross Domestic Product (GDP), foreign exchange earnings and creation of employment opportunities. Likewise, exports of palm oil also witnessed a sharp increase from 1.17 million tonnes in 1975 to 16.05 million tonnes in 2016. From merely depending on Europe as its main export destination in the early years, Malaysia has now expanded its export markets to more than 200 markets worldwide, which included the Indian sub-continent, the West Asia, Africa and Asia. In this regard, the type of export products also dramatically changed from depending on crude palm oil (CPO) (100%) to a myriad of processed palm oil products (99%) to cater to the ever increasing demand of consumers. On average, the industry contributes 5% to 7% of the country’s GDP, with export revenue for the last five years averaging at RM 64.24 billion annually. Despite attaining significant achievements in both its palm oil production and exports, Malaysia is currently facing issues of the limited arable land and labour shortage, which can affect the continued growth of the oil palm industry. Compounding this problem further, is the strong pressure exerted by non-governmental organisations (NGO) on issues of environment and so-called claims of protecting consumers’ health. It is precisely for this that the Transformasi Nasional 50 (TN50) programme envisages the adoption of mechanisation to address the issue of labour shortage and producing higher yielding clonal planting materials on a commercial basis to increase oil palm productivity. On the issue of confronting negative allegation against palm oil, continued efforts in branding palm oil as an environmentally sustainable palm oil through the adoption of the Malaysian sustainable palm oil throughout the value chain is deemed as the game changer for the industry in the future.

TISSUE-SPECIFIC PROMOTERS: THE IMPORTANCE AND POTENTIAL APPLICATION FOR GENETIC ENGINEERING IN OIL PALM – Review Article

Oil palm is the most prolific oil crop in the world with a productive life span of 20-30 years and this perenniality bestows significant advantages over other oil crops. However, the industry still faces a number of challenges and to ensure its future sustainability, efforts must be made to diversify applications to increase its economic value. Amongst potential strategies include the use of genetic engineering approaches to fulfil the needs. To ensure that expression of transgenes for the production of genetically engineered products is directed to targeted tissue(s), promoter sequences that are responsible to direct the expression of desired genes have been identified. In this review we discuss the isolation and characterisation of oil palm tissue-specific promoters from mesocarp and kernel, an inducible tissue-specific promoter from roots, and the utility of constitutive promoters. The tissue-specific and constitutive functions of these promoters were confirmed through transient expression studies in oil palm and some of the isolated promoters were further characterised using Arabidopsis as a model system. We hope that these promoters can potentially be utilised to improve oil yield and quality, to fine tune the agronomic traits, and to generate high value-added products for the oil palm.