Oil Palm Elaeis Guineensis Jacq Research Articles

The effect of aluminum treatment on metabolism in oil palm seedlings

Due to rainfall and high temperatures, the Amazonian soil undergoes changes in its source material and leaching of base cations. This results in deep, infertile, and acidic soil. Aluminum present in acidic soil impairs plant growth and development by inhibiting root formation, enzymatic reactions, absorption, transport, and nutrient utilization. This study aimed to evaluate the effects of aluminum dosage on the metabolism of the oil palm Elaeis guineensis Jacq. The study was conducted in a greenhouse at the Federal Rural University of Amazonia. The experimental design was randomized, with five replications, in which dosages of 0, 10, 20, 30, and 40 mg L-1 aluminum chloride (AlCl3.6H2O) were administered. Electrolyte leakage, nitrate, nitrate reductase, free ammonium, soluble amino acids, proline content, and soluble proteins were analyzed in the leaves and roots of the oil palm. The highest concentration of aluminum was found in the roots. AlCl3 treatment at 40 mg L-1 increased electrolyte leakage, nitrate, ammonium, and proline concentrations in the roots, and amino acid concentrations in both the leaves and roots. Furthermore, a decrease in nitrate reductase enzyme activity was observed in the roots. This study demonstrates that the oil palm has mechanisms of tolerance to aluminum toxicity.

Effect of the application of plant hormones on the formation of parthenocarpic fruits and oil production in oil palm interspecific hybrids (Elaeis oleifera Cortes x Elaeis guineensis Jacq.)

ABSTRACT Oil palm is the most important oil crop globally, accounting for almost 40% of fats and oil consumption worldwide. The OxG interspecific hybrid results from the crossing of African oil palm Elaeis guineensis Jacq. and the American oil palm Elaeis oleifera Cortes. It is a promising genotype for its high productivity, oil quality, and partial resistance to some diseases. These hybrids require assisted pollination, an activity that is time-consuming and expensive. Oil production in the OxG hybrids depends on the formation of normal (fertile) fruits and seedless (parthenocarpic) fruits. Thus, it is appealing to stimulate parthenocarpic fruits without assisted pollination. This research evaluated artificial methods of inducing parthenocarpy by applying plant hormones, and the effect on bunch formation and oil quality and its potential implementation at an industrial scale. The study was carried out in a 6-year-old hybrid (OxG) Coari x La Mé. The effects of the plant hormones indoleacetic acid (IAA), 2,4-dichlorophenoxyacetic acid (2,4-D), naphthalene acetic acid (NAA), and an ethylene precursor (ethephon) were evaluated. IAA and ethephon did not result in consistent bunch production of parthenocarpic fruits. The plants presented abnormal fruit growth, low-weight bunches, and high abortion rates. 2,4-D and NAA promoted proper parthenocarpic fruit development with oil-to-bunch (O/B) values similar to those obtained with assisted pollination. Thus, NAA and 2,4-D are an excellent alternative for oil production in the OxG hybrids that can be implemented in the African oil palm, with particular relevance that pollinators are endangered, and highly female genotypes are widely used.

Revision of the palm-pollinating weevil genus Elaeidobius Kuschel, 1952 (Curculionidae, Curculioninae, Derelomini) with descriptions of two new species

The genus Elaeidobius Kuschel, 1952 (Curculionidae, Curculioniae, Derelomini) is an Afrotropical genus associated with the male inflorescences of the oil palm Elaeis guineensis Jacq. The activity of species in this genus is critical for pollen transportation and for the fruit set of this economically important palm. In this study, the genus Elaeidobius was revised using an integrative taxonomic approach, combining traditional taxonomic treatment of species and an analysis of sequences of mitochondrial genes (COI and COII). A total of eight species is now recognized: five now formally included within it [E. bilineatus Hustache, 1924) comb. nov., E. kamerunicus (Faust, 1898) comb. nov., E. plagiatus (Fåhraeus, 1844) comb. nov., E. singularis (Faust, 1898) comb. nov., E. subvittatus Faust, 1898)], one transferred here from the genus Prosoestus to the genus Elaeidobius, E. spatulifer (Marshall, 1950) comb. nov., and two newly described species (E. pilimargo Haran & Kuschel sp. nov., E. piliventris Haran & Kuschel sp. nov.). The following new synonymies are proposed: Prosoestus armatus Voss, 1956 = E. bilineatus (Hustache, 1924) comb. nov. and Derelomus uelensis Hustache = E. singularis (Faust, 1898). An illustrated key to the species is provided with photographs of the adult habitus and male genitalia.

Effect of NaCl on the development of the oil palm vascular wilt fungus, Fusarium oxysporum f. sp. elaeidis.

Oil palm Elaeis guineensis Jacq. (Arecaceae) is one of the cash crops that mainly contributes to the gross domestic production of growing countries. This crop is grown worldwide throughout the humid intertropical belt. Its production in Africa is mainly threatened by the telluric fungus Fusarium oxysporum f. sp. elaeidis, causal agent of the oil palm vascular wilt. It has been reported that some environmental factors, such as soil and air salinity, may determine the survival, development and severity of phytopathogenic agents including Fusarium. The purpose of this study was to evaluate the effect of NaCl on growth, reproduction and pathogenic traits of this fungus by measuring mycelium daily growth, mycelium dry weight, sporulation rate, germination rate and number of infectious spores under four NaCl concentrations (0 g.L-1, 2.5 g.L-1, 5 g.L-1 ,10 g.L-1) of culture medium (MM solid medium and Armstrong liquid medium). The results indicated that NaCl reduced the radial daily growth and mycelium dry weight. In addition, the NaCl reduced significantly the sporulation rate and number of infectious spores while increasing the germination rate. Overall, these results indicated the negative NaCl effect on the development and the fitness of this pathogenic fungus. Thus, NaCl inputs appeared to be a potential solution for managing Fusarium oxysporum f. sp. elaeidis in the field, if a good balance between a decrease of disease incidence and yield loss is reached.

Characterization of promoter of EgPAL1, a novel PAL gene from the oil palm Elaeis guineensis Jacq.

The oil palm EgPAL1 gene promoter and its regulatory region were functional as a promoter in the heterologous system of Arabidopsis according to the cis-acting elements present in that region. The promoter was developmentally regulated, vascular tissue specific and responsive to water stress agents. Phenylalanine ammonia lyase (PAL, EC 4.3.1.24) is the key enzyme of the phenylpropanoid pathway which plays important roles in plant development and adaptation. To date, there is no report on the study of PAL from oil palm (Elaeis guineensis), an economically important oil crop. In this study, the 5' regulatory sequence of a highly divergent oil palm PAL gene (EgPAL1) was isolated and fused with GUS in Arabidopsis to create two transgenic plants carrying the minimal promoter with (2302bp) and without its regulatory elements (139bp). The regulatory sequence contained cis-acting elements known to be important for plant development and stress response including the AC-II element for lignin biosynthesis and several stress responsive elements. The promoter and its regulatory region were fully functional in Arabidopsis. Its activities were characterised by two common fundamental features of PAL which are responsive to plant internal developmental programme and external factors. The promoter was developmentally regulated in certain organs; highly active in young organs but less active or inactive in mature organs. The presence of the AC elements and global activity of the EgPAL1 promoter in all organs resembled the property of lignin-related genes. The existence of the MBS element and enhancement of the promoter activity by PEG reflected the behaviour of drought-responsive genes. Our findings provide a platform for evaluating oil palm gene promoters in the heterologous system of Arabidopsis and give insights into the activities of EgPAL1 promoter in oil palm.

Effects of shading, irrigation and mycorrhizal inoculation on growth and development of oil palm Elaeis guineensis Jacq. (Magnoliophyta: Arecaceae) seedlings in the nursery

Experiments were conducted to examine the growth and development of oil palm Elaeis guineensis Jacq. (Magnoliophyta: Arecaceae) seedlings subjected to shading, irrigation regimes and mycorrhizal inoculation in the dry season. Treatments were 2 x 2 x 2 factorial combination consisting of shade and no-shade (open sun), 7 and 14 day irrigation intervals and mycorrhizal inoculation or non-inoculation. Seedlings that were grown under shade and irrigated weekly produced highest number and length of fronds, and shoot, leaf and frond weights in addition to taller plants compared to open sun (unshaded) seedlings. Across irrigation treatments, unshaded seedlings had lower weights of leaf, frond and shoot biomass. The effects of shade treatments were significant on plant height and frond length from 2 to 20 weeks after planting. The seedlings irrigated fortnightly produced longer roots compared with the unshaded and weekly irrigated. Fortnight irrigation enhanced root development compared with weekly irrigation. Shading and weekly irrigation significantly enhanced soil moisture contents and seedling water use efficiency compared with the unshaded. Shaded seedlings irrigated weekly used larger amount of water compared with fortnight irrigation. Significant interactions were obtained between shade and irrigation regimes for most of the growth parameters measured. Mycorrhizal inoculation, shaded and weekly irrigated seedlings were more vigorous compared with the unshaded and non-inoculated.

Oil palmin vitroregeneration: microdensitometric analysis during reproduction and development

An extensive microdensitometric analysis was performed in oil palm Elaeis guineensis Jacq. during the establishment of a new embryogenic culture, on new regenerated plants at different times, and f...

Differential abundance analysis of mesocarp protein from high- and low-yielding oil palms associates non-oil biosynthetic enzymes to lipid biosynthesis.

BackgroundThe oil palm Elaeis guineensis Jacq. which produces the highest yield per unit land area of the oil crops is the most important commercial oil crop in South East Asia. The fleshy mesocarp of oil palm fruit, where oil is mostly derived from, contains up to 90 % dry weight of oil (one of the most concentrated in plant tissues). Hence, there is attention given to gain insights into the processes of oil deposition in this oil rich tissue. For that purpose, two-dimensional differential gel electrophoresis (DIGE) coupled with western assays, were used here to analyze differential protein levels in genetically-related high-and low-yielding oil palm mesocarps.ResultsFrom the DIGE comparative analysis in combination with western analysis, 41 unique differentially accumulated proteins were discovered. Functional categorization of these proteins placed them in the metabolisms of lipid, carbohydrate, amino acids, energy, structural proteins, as well as in other functions. In particular, higher abundance of fructose-1,6-biphosphate aldolase combined with reduced level of triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase may be indicative of important flux balance changes in glycolysis, while amino acid metabolism also appeared to be closely linked with oil yield.ConclusionsForty-one proteins in several important biological pathways were identified as exhibiting differential in abundance at critical oil production stages. These confirm that oil yield is a complex trait involving the regulation of genes in multiple biological pathways. The results also provide insights into key control points of lipid biosynthesis in oil palm and can assist in the development of genetic markers for use in oil palm breeding programmes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12953-015-0085-2) contains supplementary material, which is available to authorized users.

Description of the males of Lincus singularis and Lincus incisus (Hemiptera: Pentatomidae: Discocephalinae)

The Neotropical Lincus Stal, 1867 includes 35 species, thirteen of which are known only from females. Several species are vectors of Phytomonas staheli McGhee & McGhee, 1979, a trypanosomatid parasitic in palm-trees in South America that causes hart-rot, sudden and slow wilt diseases. The hitherto unknown males of L. singularis Rolston, 1983 (swollen head species group found in the oil palm Elaeis guineensis Jacq.), and L. incisus Rolston, 1983 (hatchet-lobed species group; found in the coconut tree Cocos nucifera L.), are described with emphasis on the morphology of the genitalia, and taxonomic remarks are provided. Males of L. singularis can be distinguished from other species included in swollen head group by their pronotal lobes with anterior and posterior margins subparallel and projected laterally from the eye margin, while males of L. incisus can be distinguished from the species of the swollen head group by an obtuse projection with a deepest incision and several additional diagnostic characters of the genitalia.

Complementary Diet of Cathartes burrovianus (Cathartidae) With Fruit Elaeis guineensis (Arecaceae)

The mangrove swamps of the Guapi-Mirim Environmental Protection Area are rich in animal diversity. Due to its considerable size there is a generous supply of prey for any predator as well as significant food resources for animal scavengers. The vultures, which are carrion or predatory birds are included in the order Cathartiformes (Cathartidae) and the most common species in Brazil are: Cathartes aura (Linnaeus, 1758), Cathartes burrovianus Cassin, 1845; Cathartes melambrotus Wetmore, 1964; Coragyps atratus (Bechstein, 1793) and Sarcoramphus papa (Linnaeus, 1758). In the mangrove swamps of this protected area three species of vultures are commonly seen: C. aura, C. burrovianus e C. atratus. These three species basically have a diet of animal carcasses. All the Cathartes burrovianus observations carried out in this study were made in a small part of the mangrove swamps in the Guapi-Mirim APA, located in the district of Itambi, Itaboraí, Rio de Janeiro, Brazil. The observations were made every two weeks for a year and photography was used to record the birds. A total of 78 photographic observations were made of these birds (C. burrovianus) feeding on the fruit of the oil palm Elaeis guineensis Jacq. 1897. As the mangrove swamp has abundant food resources throughout the year, it was concluded that C. burrovianus feeds on the fruits of the palm E. guineensis not only as an alternative food in the absence of carcasses, but also a complement to their dietary needs. It is the first record of this feeding behavior. This fact may be related to the higher digestibility of carcasses consumed by these animals.

Morpho-agronomic and molecular characterisation of oil palm Elaeis guineensis Jacq. material from Angola

The characterisation of phytogenetic resources is used to improve conservation strategies, promote new sources of plant material, and design breeding strategies. In this study, we evaluated oil palm material with nine morpho-agronomic traits and 30 microsatellite markers (Simple Sequence Repeats; SSRs) that had been previously collected in five geographical regions of Angola. The analysis of variance for components of bunch production and oil yield showed highly significant (p < 0.001) statistical differences between geographical regions and among families for all traits evaluated. The SSRs were highly informative, suggesting high genetic diversity (HT = 0.666) among the accessions evaluated. However, the clustering pattern at both morpho-agronomic and molecular levels did not match the geographical distribution of accessions, showing a low genetic differentiation (GST = 0.039) between regions. On the other hand, genotypic (GST = 0.150) and phenotypic differences were found among families, which could offer the potential for future genetic gains in the oil palm. The information generated indicates that the evaluated accessions have desirable characteristics that should be included in breeding programs, which could expand the genetic basis of the crop.

Molecular cloning and expression of a cDNA encoding 1-deoxy- d-xylulose-5-phosphate synthase from oil palm Elaeis guineensis Jacq.

In higher plants, there are two pathways leading to the formation of isoprenoids: the acetate/mevalonate (MVA) pathway and the recently discovered 2C-methyl- d-erythritol-4-phosphate (MEP) pathway. The initial step on the MEP pathway is the condensation of pyruvate and glyceraldehyde-3-phosphate yielding 1-deoxy- d-xylulose-5-phosphate (DXP). The reaction is catalyzed by 1-deoxy- d-xylulose-5-phosphate synthase (DXS), and is encoded by the dxs gene. In this study, parts of dxs have been cloned from young leaves and mesocarp of oil palm ( Elaeis guineensis Jacq., Tenera) The surprising results show that there are at least two dxs genes encoding DXS in different organs of oil palm, dxs1 in leaves and dxs2 in fruits. Cloning of full-length cDNA encoding dxs1 by the RLM-RACE (RNA ligase-mediated rapid amplification of 5 ′ and 3 ′ cDNA ends) method demonstrated that the cDNA contained an open reading frame of 2301 bp encoding a deduced peptide of 707 amino acid residues with a predicted molecular mass of 76.4 kDa and isoelectric point of 7.0. Expression of dxs2 and dxr transcript levels in oil palm fruits from each developmental stage were analyzed by a semiquantitative RT-PCR method. The level of dxs2 transcripts increases with the time after fertilization and reaches its maximum after 18 weeks while the expression of dxr is unchanged. The pattern of dxs2 transcripts appears to correlate with β-carotene accumulation during oil palm fruit ripening thus supports the assumed role of the dxs gene in carotenoid biosynthesis by the MEP pathway.