African Oil Palm Elaeis Guineensis Research Articles

The origin of an extreme case of sister‐species sympatry in a palm‐pollinator mutualistic system

AbstractAimMutualistic systems involving plants and brood pollinators show intriguing cases where a single plant is pollinated by several closely related sympatric species. This study aims at identifying the mechanisms involved in such an extreme case, where 10 sympatric weevil species are only associated with African oil palm inflorescences. We assessed the patterns and timing of speciation of this peculiar assemblage to explore the main drivers of its diversification.LocationTropical Africa.TaxonThe African oil palm Elaeis guineensis Jacquin (Arecaceae, Cocoseae), weevil genera Elaeidobius Kuschel and Prosoestus Faust (Curculionidae, Derelomini).MethodsWe first reassessed the status of the weevil species assemblage associated with the African oil palm based on a range of molecular species delimitation analyses. Second, we reconstructed a dated molecular phylogeny using Bayesian inference and maximum likelihood and carried out historical biogeographical analyses accounting for the main biogeographical barriers in tropical Africa.ResultsOur analyses generally confirm the validity of the species associated with the African oil palm and indicate that they form a monophyletic group. Dating analyses indicate that they originated about 7–8 million years ago (Mya) and that most speciation events occurred during the Pliocene and Pleistocene. Historical biogeography analyses reveal that one geographical barrier played a bigger role during their diversification. Age estimates suggest that extant weevil species remained in sympatry along the range of their host during the last 0.2 Mya.Main conclusionsThis case represents a remarkable example of a speciose mutualistic monophyletic insect assemblage. Our results indicate that past climatic oscillations in Western and Central Africa – where cycles of range contractions and expansions of the host drove the divergence of the weevils in allopatry – and the predominant role of a mountain range were instrumental in the emergence of the sympatric assemblage.

Insect flower-visitors of African oil palm Elaeis guineensis at different sites and distances from natural vegetation in Uganda

This survey aimed at generating information to guide improvement of oil palm fruit-set in Uganda by testing the hypothesis that diversity and abundance of oil palm insect flower-visitors were influenced by sampling site, distance from natural vegetation and flower sex. Sampling was done on male and female oil palm flowers from (i) five oil palm experimental fields in different districts and (ii) oil palm plantations on Bugala Island on Lake Victoria. The plantations on Bugala Island were subdivided into near (0–15 m) and far (100–200 m) from natural vegetation. We recorded 162,677 insects in 23 morpho-species, dominated by weevils in the genera Elaeidobius and Metamasius (Family: Curculionidae); beetles (Families: Nitidulidae, Staphylinidae and Scarabidae); Diptera (Families: Muscidae, Drosophilidae and Platystomatidae); and honeybees (Apis mellifera), respectively. All morpho-species occurred on both flower sexes, except four Elaeidobius spp which occurred on only male flowers. All morpho-species recorded on both flower sexes were more abundant on male than female flowers, except Apis mellifera and one Elaeidobius sp whose mean counts were comparable between flower sexes. The insects were more abundant and divers on oil palm trees near a natural vegetation than on those positioned farther away; and on the Island than the mainland sites. This suggests a need for location specific interventions and manipulation of natural vegetation in designing strategies for boosting oil palm pollination in Uganda. Further research is necessary to understand ecology and biology of the identified oil palm flower visitors to boost oil palm pollination in Uganda.

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.

Multilocus phylogeography of the world populations of Elaeidobius kamerunicus (Coleoptera, Curculionidae), pollinator of the palm Elaeis guineensis.

Elaeidobius kamerunicus Faust (Coleoptera, Curculionidae) is one of the specific pollinators on inflorescences of the African oil palm Elaeis guineensis Jacquin. This derelomine weevil is native to tropical Africa. During the late 20th century, it was introduced into all tropical regions where E. guineensis is grown, in order to improve its pollination and fruit set. Despite an overall success, a decline in pollination efficiency has been documented in several regions. In this study, we reconstructed a multilocus phylogeography of the world populations of E. kamerunicus, in order to explore its genetic diversity in its native and introduced ranges. Our results showed that African populations of E. kamerunicus are forming two differentiated mitochondrial clusters in West and central Africa, forming a contact zone along the Cameroon Volcanic Line. The existence of this sharp contact zone along this weak altitudinal barrier suggests that other parameters, such as climate, may be driving the distribution of populations. A differential genetic structure between mitochondrial and nuclear genes, and the strong level of genetic structure of the mitochondrial gene, also suggest sex-biased dispersal in this species, with males dispersing more than females. The genetic structure inferred from Asian and South American populations suggests that they originate from populations of both western and central tropical Africa and that a bottleneck has probably been experienced by these populations.

Competitiveness Sensitivity of Oil Palm Farming on Suboptimal Land at Musi Rawas Residence

Palm oil is an edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of the oil palm, primarily the African oil palm Elaeis guineensis. Oil palm is one of agriculture comodity that can increase farmers income, provide raw material on manufacture industry which can create added value. The expansion of oil palm farming in Indonesia has shifted the use of mineral land to suboptimal land which is currently available in many place in Indonesia. Generally the aim of this research is to anylize the competitiveness sensitivity of oil palm farming. Specifically this research wants to anylize the sensitivity on input-output changing, and to anylize the impact of government policy on input-output when facing fluctuation price. In order to reach the goal of this research we used Policy Anlayisis Matrix (PAM). The result of this research shows that partially the declining of price, declining of output volume and increasing input price PCR value and DRCR < 1, which means that the oil palm farming on suboptimal land has competitivenes, and the absence of government policy on determaining input price nor output price on oil palm farming in at suboptimal land. While simultanously shows that the fluctuation of input and output price causes value of PCR dan DRCR > 1 with PCR value 1,12 and DRCR value 1,04, means that oil palm farming on suboptimal land at Musi Rawas Regency not feasible and has no competitiveness. It means that government policy needed to protect input price in oil palm farming on suboptimal land. Therefore government support and guidence in oil palm farming technology on suboptimal land also needed to increase the production of oil palm farming on suboptimal land.

Habitat utilisation and nesting behaviour of two sympatric weavers in Mbalmayo District, Cameroon

Avian ecology and behaviour data provides crucial information for bird conservation and management, but are still missing for many species, particularly in developing countries. This study examines habitat utilisation, nesting behaviour, anthropogenic disturbances and impacts on agricultural crops of Village Weaver Ploceus cucullatus and Vieillot’s Black Weaver Ploceus nigerrimus in Mbalmayo District, Cameroon. Abundance was estimated by nest counts and point counts of birds at 40 previously located colonies, where also tree metrics and anthropogenic disturbances were measured. In total, more than 1 700 birds of the two species were estimated within a 9 km2 study area, divided into two blocks and five different habitat types. Village Weavers were generally more abundant, especially in the urban habitat, whereas Vieillot’s Black Weavers were most numerous in the rural habitat. Among the tree species used for nesting, mango Mangifera indica and African border tree Newbouldia laevis had the highest nest counts, which also was positively related to canopy cover diameter. Traffic noise disturbance was associated with lower bird and nest counts, whereas the opposite was observed on farming disturbance. The relative impacts on agricultural crops were estimated for African oil palm Elaeis guineensis (38%), maize Zea mays (36%), Musa spp. (18%) and Mangifera indica (8%). The implications for long-term coexistence between farmland birds and humans are discussed, and the challenge is to minimise both kinds of bird–human interactions, i.e. anthropogenic disturbances and agricultural crop damage.

Loss of Karma transposon methylation underlies themantled somaclonal variant of oil palm.

Somaclonal variation arises in plants and animals when differentiated somatic cells are induced into a pluripotent state, but the resulting clones differ from each other and from their parents. In agriculture, somaclonal variation has hindered micropropagation of elite hybrids and genetically modified crops, but the mechanism remains a mystery1. The oil palm fruit abnormality, mantled, is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for oil production2–4. Widely regarded as epigenetic5, mantling has defied explanation, but here we identify the MANTLED gene using Epigenome Wide Association Studies. DNA hypomethylation of a LINE retrotransposon related to rice Karma, in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is associated with alternative splicing and premature termination. Dense methylation near the Karma splice site (the Good Karma epiallele) predicts normal fruit set, while hypomethylation (the Bad Karma epiallele) predicts homeotic transformation, parthenocarpy and dramatic loss of yield. Loss of Karma methylation and small RNA in tissue culture contributes to the origin of mantled, while restoration in spontaneous revertants accounts for non-Mendelian inheritance. The ability to predict and cull mantling at the plantlet stage will facilitate the introduction of higher performing clones and optimize environmentally sensitive land resources.

Indigenous fungal entomopathogens associated with the oil palm leaf miner <i>Coelaenomenodera lameensis</i> Berti and Mariau in Ghana

Background and Objective : The oil palm leaf miner Coelaenomenodera lameensis (Coleoptera: Chrysomelidae) is the most devastating insect pest of the African oil palm Elaeis guineensis Jacquin. Like most insect control programmes, control in Ghana has been through the use synthetic insecticides. The over-dependence on chemical control has brought in its wake adverse effects such as toxicity to the user and non-targeted organism. Entomopathogens have proven to be effective in the management of many insect species and these are environmentally-friendly. In this study we investigated reports by field workers of Council of Scientific and Industrial Research (CSIR)-Oil Palm Research Institute of Ghana who observed the presence of mycelia on the cuticle of cadavers of C. lameensis in their daily phytosanitary surveillance. Methodology and Results : Field surveys were conducted in three oil palm plantations viz: CSIR-Oil Palm Research Institute and a commercial oil palm farm, both at Kusi in the Eastern Region, and Twifo Oil Palm Plantation of Unilever Ghana Limited at Twifo Praso in the Central Region of Ghana to collect cadaver of C. lameensis infected with fungi. The cadavers were aseptically cultured in the laboratory on Potato Dextrose Agar and fungi isolated and identified. A total of 17 fungal species were isolated from cadavers of the leaf miner. These include Aspergillus sp, Metarhizium sp, Paecilomyces sp, Penicillium sp, Pestalotia sp, Rhizoctonia sp, and three unidentified species. Bioassays conducted to ascertain the pathogenicity of the fungi against C. lameensis adult showed an overall mortality ranging between 12.5% - 77.5% within 7 days. Growth of mycelia on treated dead insects ranged from 0% - 47.5%. The unidentified fungus coded BKFF was found to be the most lethal inducing about 77% mortality in the insect and thus more entomopathogenic, followed by Paecilomyces sp. (Ioprik31 and Pestalotia sp. (CKFF) (both 65%) whilst Rhizoctonia sp was found to be the least lethal. Conclusion and application of findings : This study presents important naturally occurring fungal species associated with the oil palm leaf miner C. lameensis in the field which famers can utilize as a control option upon further field studies. Key words : Coelaenomenodera lameensis , entomopathogenic fungi, isolate, pathogenicity, mycelia

Oil palm genome sequence reveals divergence of interfertile species in Old and New worlds.

Oil palm is the most productive oil-bearing crop. Planted on only 5% of the total vegetable oil acreage, palm oil accounts for 33% of vegetable oil, and 45% of edible oil worldwide, but increased cultivation competes with dwindling rainforest reserves. We report the 1.8 gigabase (Gb) genome sequence of the African oil palm Elaeis guineensis, the predominant source of worldwide oil production. 1.535 Gb of assembled sequence and transcriptome data from 30 tissue types were used to predict at least 34,802 genes, including oil biosynthesis genes and homologues of WRINKLED1 (WRI1), and other transcriptional regulators1, which are highly expressed in the kernel. We also report the draft sequence of the S. American oil palm Elaeis oleifera, which has the same number of chromosomes (2n=32) and produces fertile interspecific hybrids with E. guineensis2, but appears to have diverged in the new world. Segmental duplications of chromosome arms define the palaeotetraploid origin of palm trees. The oil palm sequence enables the discovery of genes for important traits as well as somaclonal epigenetic alterations which restrict the use of clones in commercial plantings3, and thus helps achieve sustainability for biofuels and edible oils, reducing the rainforest footprint of this tropical plantation crop.

Reproductive developmental complexity in the African oil palm (Elaeis guineensis, Arecaceae)

Species of the palm family (Arecaceae) are remarkably diverse in their inflorescence and floral morphologies, which make them a particularly interesting group for studies of reproductive development and its evolution. Using light and scanning electron microscopy, we describe inflorescence and flower development in the African oil palm Elaeis guineensis from the initiation of the inflorescence meristem to flower maturity. In mature palms, the inflorescence develops over 2-3 years and is characterized by individual stages within which differentiation may be either relatively slow, as in the case of early inflorescence meristem development, or rapid, as in the case of flower organogenesis. The female inflorescence bears floral triads composed of single pistillate flowers flanked by two abortive staminate flowers, whereas the male inflorescence contains single functional staminate flowers. This suggests a possible evolutionary movement from an ancestral hermaphrodite inflorescence form containing fully functional floral triads to the situation of temporal dioecy observed at present. Wild type flowers are compared to those bearing an epigenetic homeotic abnormality, known as mantled, involving an alteration of the identity of the organs in the fertile and sterile androecium.

Purification and stability of peroxidase of African oil palm Elaies guineensis.

In the previous work, after screening tropical plants (43 species) for peroxidase activity, high activity has been detected in leaves of some palms and especially African oil palm Elaeis guineensis. This palm is widely cultivated in Colombia and presents a promising source for the industrial production of peroxidase. The initial enzyme isolation included homogenization and extraction of pigments using aqueous two phase polymer system. Initially, traditional system, formed by polyethyleneglycol/K2HPO4, was used. The replacement of K2HPO4 with (NH4)2SO4 allowed direct application of the salt phase with accumulated peroxidase on a Phenyl-Sepharose column. The final purification was carried out by liquid chromatography on Sephacryl S200 and DEAE-Toyopearl columns. The specific activity of the purified peroxidase measured toward guaiacol was 4300 units per mg of protein. The molecular weight and isoelectric point for palm peroxidase were 57.000 and 3.8, respectively. Palm peroxidase possesses uniquely high thermostability and is more stable in organic solvents than horseradish peroxidase is.