Hernán Mauricio Romero

Lipase activity, mesocarp oil content, and iodine value in oil palm fruits of Elaeis guineensis, Elaeis oleifera, and the interspecific hybrid O × G (E. oleifera × E. guineensis).

BACKGROUND One factor affecting crude palm oil quality is the formation of free fatty acids (FFA), often attributed to the hydrolytic action of mesocarp lipase. The aim of this work was to evaluate the enzyme behavior and to look toward new genotypes with low FFA production, high yield, and better oil quality. RESULTS Lipase activity was strongly activated at low temperatures (5 °C). At this temperature PLL, SOO, POL, and POO (P, palmitic; L, linoleic; S, stearic; O, oleic) were the most hydrolyzed triacylglycerols in Elaeis guineensis fruits. Ethylene production decreased from 36 nL g(-1) h(-1) at room temperature to 2 nL g(-1) h(-1) at 5 °C. Lipase activity of E. guineensis, the E. oleifera × E. guineensis (O×G) hybrid, and E. oleifera were 52.7%, 32.9%, and <0.6% FFA, respectively. The E. guineensis showed oil in the mesocarp of 54.7%, followed by the O×G hybrid (47.0%), and E. oleifera (13.6%), and the iodine values were 52.0, 66.3, and 77.4 g I(2) 100 g(-1), respectively. CONCLUSIONS This work allowed the identification of interspecific O×G hybrids as promising crosses with less lipase activity and higher iodine value than E. guineensis. Although O×G crosses produce less oil in the mesocarp than commercial E. guineensis; this feature could be improved by further breeding to introduce new genes from E. oleifera into the hybrids.

Phenology of the oil palm interspecific hybrid Elaeis oleifera × Elaeis guineensis

Oil palm is one of the most important oil crops in the world. Because of its high productivity and perennial nature, it has been expanding quickly. Commercial plantations consist mostly of the African palm E. guineensis Jacq. However, producers in Latin America are increasingly planting the O × G interspecific hybrid, a cross between African palm (E. guineensis) and the American palm (E. oleifera (Kunth) Cortes). This interspecific hybrid has emerged as a promising solution to diseases such as the bud rot of oil palm because of the apparent partial resistance of this genotype to the disease. This work studied and described the phenology of the O × G interspecific hybrid. The phenology stages were coded using the BBCH scale. The scale for the phenophases was defined using a three-digit code. Due to the nature of the palm, no descriptions were used for stage two (formation of side shoots/tillering) and stage four (development of harvestable vegetative plant parts or vegetative reproductive organs) because these stages do not apply to oil palm. The scale was constructed using germinating seeds, pre-nursery and nursery plants and five year-old palms. For the description of the stem elongation, different age palms of the same O × G hybrid were used. Observations were performed during an 18-month period. Additionally, the interval for the change from one phenology stage to another was determined both in days and degree-days (DD). The interspecific O × G hybrid required 6408 DD from when the spear leaf unfolds until the bunch was ripened and harvested, and 4427.6 DD from leaf unfolding to anthesis.

Effect of fruit ripening on content and chemical composition of oil from three oil palm cultivars (Elaeis guineensis Jacq.) grown in Colombia.

A series of physical and chemical changes occur as oil palm fruits ripen in the bunch. We evaluated changes in lipid content in the mesocarp and fruits, and the chemical composition of fatty acids (FA), triacylglycerol (TAG), tocols, and carotenes of the lipids extracted from fruits of three commercial tenera cultivars, namely, Deli×La Mé, Deli×Ekona, and Deli×Avros, planted in two different geographical regions in Colombia, during the ripening process 12, 14, 16, 18, 20, 22, and 24 weeks after anthesis (WAA). It was found that 12 WAA the mesocarp contained less than 6% of total lipids. Oil content increased rapidly after 16 WAA, reaching the maximum oil content of 55% in fresh mesocarp and 47% in fresh fruits at 22 WAA, which was found the optimal time for harvesting. Changes in FA and TAG showed that total polyunsaturated fatty acids (PUFA) and triunsaturated triacylglycerols (TUTAG) decreased, while total saturated fatty acids (SFA) and disaturated triacylglycerols (DSTAG) increased, over the ripening period. Changes in FA were mainly observed in palmitic, oleic, linoleic, and linolenic acids, and in POP, POO, POL, and OLL for the TAGs evaluated. Levels of tocols changed depending on whether they were tocopherols or tocotrienols. In the earliest stages tocopherols were predominant but decreased rapidly from 6600 mg kg(-1) of oil at 14 WAA to 93 mg kg(-1) of oil at 22 WAA. Tocotrienols appeared at the same time as oil synthesis started, and became the main source of total tocols, equivalent to 87% in total lipids extracted.

Molecular characterization of oil palm Elaeis guineensis Jacq. materials from Cameroon

The narrow genetic base of existing commercial oil palm cultivars has prompted oil palm breeders to give increased importance to augmenting these genetic resources because the sustainable development of the crop depends largely on the availability of genetic diversity and its use. Therefore, the purpose of this study was to conduct a molecular characterization of an ex situ collection of oil palm Elaeis guineensis Jacq. populations from the Republic of Cameroon using microsatellite molecular markers. Overall, 31 simple sequence repeats were polymorphic, with a total of 223 alleles, 78.4% of which were found at low frequency. The total genetic diversity was relatively high (HT ¼ 0.673). The genetic differentiation between geographical regions was low (GST ¼ 0.023, P ¼ 0.001), and between families it was high (GST ¼ 0.166, P ¼ 0.001), showing greater variation between families than among geographical regions. The molecular data indicate that genetic diversity among the genotypes evaluated is mainly distributed within regions, suggesting that there is no isolation by geographical distance and that all the sampled individuals form a single diverse population. Therefore, it was concluded that a relatively low number of accessions (120 in the analysed case) that includes at least one representative of each family would allow us to efficiently collect almost the entire genetic diversity of Cameroon within the collection studied. This will allow for the efficient use of genetic resources and a reduction in morpho-agronomic characterization costs.

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.

Genetic and phenotypic diversity of natural American oil palm (Elaeis oleifera (H.B.K.) Cortés) accessions

Elaeis oleifera has become a valuable genetic resource for the production of interspecific hybrids of E. oleifera (H.B.K) Cortés × Elaeis guineensis Jacq. to address plant disease problems affecting oil palm cultivation. In this study, we evaluated the phenotypic and genetic diversity of accessions of E. oleifera from different countries in South America using morpho-agronomic traits and microsatellite markers (Simple Sequence Repeats, SSRs). Analyses of variance for yield and bunch components demonstrated statistically significant differences among countries and geographical regions for several of the traits evaluated. SSR marker analyses revealed high genetic diversity (HT = 0.797) and the presence of specific alleles by each country of origin from E. oleifera. The clustering topology obtained showed four distinguishable E. oleifera groups, which matched the geographical distribution of the accessions and thus exhibited a high genetic differentiation (GST = 0.512) and a low gene flow Nm = 0.238 among countries. The results enabled us to demonstrate that E. oleifera has a specific genetic structure and a phenotypic variability with different characteristics between origins, and the accessions from each country of origin contributed to the increase in total genetic diversity. A core collection was defined based on the accuracy of the classification of individuals with respect to their country of origin. The information reported in this study will be of great interest to oil palm researchers because new strategies for breeding programs can be developed based on these advances.