Assessment of Inoculation Methods of Thielaviopsis paradoxa (De Seynes) Höhn into Oil Palm Seedlings under Greenhouse Conditions

Oil palm (Elaeis guineensis Jacq. and Elaeis Oleifera Cortes) is one of the most important oil crops in the world. Colombia is the fourth-largest oil palm producer worldwide. However, oil palm diseases are a significant factor affecting yield. Thielaviopsis paradoxa (De Seynes) Höhn is a pathogen that affects young palm trees, causing spear rot. Four disease establishment methods were studied to replicate, in a controlled environment, the symptoms of the disease found in the field. Young palm trees were inoculated with a suspension of endoconidia using either local infiltration, drip, scissor cut, or direct contact with agar blocks bearing mycelia and conidia. The effects of the inoculation methods were studied in dose-method-disease severity experiments conducted in a greenhouse under controlled conditions. All four methods resulted in T. paradoxa infections and the development of symptoms of the disease. The disease severity was correlated with the method and dose of inoculation. In trials to test Koch’s postulates, T. paradoxa was isolated from areas of disease progression in the inoculated trees, but the teleomorph Ceratocystis paradoxa (Dade) Moreau was not observed. A photographic record of the infection process at different times post-infection was compiled. Given that establishing the disease through artificial inoculation is essential for assessing plant pathogenesis, this study determined that the local infiltration method (1 × 106 endoconidia mL−1) and a 3–7 day incubation period were critical for the development of symptoms as severe as those observed in natural infections in the field.

Minor Compounds of Palm Oil: Properties and Potential Applications

The oil contained in ripe fruits produced by cultivars of African oil palm Elaeis guineensis Jacq., as well as that obtained from fresh fruit bunches of certain inter-specific hybrid cultivars derived from crossbreeding between Elaeis oleifera (Kunth) Cortés and E. guineensis Jacq., have shown to be lipid substrates rich in valuable phytochemicals with exceptional biological properties and functional applications for multiple human health tasks. Eight isoforms of vitamin E (four tocopherols and four tocotrienols), α- and β-carotene, squalene, and various phenolic structures, make up the largest group of minor compounds in palm oil and are essential nutrients with physiological functions that include, but are not limited to their antioxidant properties. Vitamin E regulates the redox (oxidation-reduction) balance in the body, and compounds such as squalene and carotenoids are ubiquitously distributed throughout the body, including cell membranes and lipoproteins. Several studies suggest that regular intake of foods rich in this group of phytonutrients minimizes the reactivity of oxidative chemical species at the cellular level and serves as an effective adjunct in the treatment of oxidative stress.

Cotesia cassina sp. nov. from southwestern Colombia: a new gregarious microgastrine wasp (Hymenoptera, Braconidae) reared from the pest species Opsiphanes cassina Felder & Felder (Lepidoptera, Nymphalidae) feeding on Elaeis oil palm trees (Arecaceae)

A new species of microgastrine wasp, Cotesia cassina Salgado-Neto, Vásquez & Whitfield, sp. nov., is described from southwestern Colombia in Tumaco, Nariño. This species is a koinobiont gregarious larval endoparasitoid, and spins a common mass of cocoons underneath the host caterpillars of Opsiphanes cassina (Felder & Felder) (Lepidoptera, Nymphalidae), feeding on oil palm trees (interspecific hybrid Elaeis oleifera × E. guineensis) (Arecaceae). While superficially similar, both morphologically and biologically, to C. invirae Salgado-Neto & Whitfield from southern Brazil, the two species are distinct based on DNA barcodes, host species, geographical range and morphological characters.

Identifikasi SNP genom pada populasi Elaeis guineensis x Elaeis oleifera

Usaha pencarian marka DNA yang berhubungan dengan sifat yang diinginkan pada Elaeis oleifera guna introgresi sifat tersebut ke genome Elaeis guineensis memerlukan marka DNA yang polimorfik. Untuk menghasilkan marka DNA yang polimorfik dengan jumlah banyak, identifikasi SNP genom dilakukan melalui pengurutan kembali (resequencing) 12 individu contoh populasi hibrida E. guineensis x E. oleifera (hibrida OxG), yaitu E. oleifera tipe liar, F1 hibrida interspesifik, pseudo-backcross dan material maju E. guineensis, menggunakan next generation sequencing (NGS). Read (urutan basa yang “dibaca”/merupakan keluaran mesin NGS) dari 12 contoh memiliki mutu yang baik dan 96% total read yang disaring dapat dilakukan demultipleks dan ditentukan pada contoh yang sesuai. Setelah proses penyaringan dan pemotongan, 84% read dapat digunakan untuk pemetaan genom dan menghasilkan 5,7X hingga 10,42X cakupan genom. Dari 34.410.224 SNP yang teridentifikasi, 98,7% diantaranya adalah varian non-coding, dan berdasarkan lokasi, 69,1% total SNP adalah SNP intergenic. Sebanyak 5.618 SNP dari total SNP yang dihasilkan dibuktikan menggunakan targeted genotyping by sequencing pada 500 individu contoh. Sebanyak 74% SNP yang digunakan bermutu tinggi yang dibaca pada setidaknya 95% contoh. Principal component analysis menggunakan SNP tersebut mampu mengidentifikasi setiap latar belakang genetik contoh. Pembuktian tersebut menyimpulkan bahwa identifikasi SNP yang dilakukan melalui pengurutan kembali menghasilkan SNP bermutu tinggi yang dapat digunakan untuk pengembangan marka DNA yang dapat diperbantukan pada seleksi populasi pemuliaan E. guineensis x E. oleifera.

Genome-Wide Association Study (GWAS) for Bunch Components of The Interspecific Population of Elaeis oleifera and Elaeis guineensis

The oil palm breeding program for the species Elaeis guineensis and the backcross Elaeis oleifera is running slowly because oil palm is an annual plant. Therefore, it is necessary to have an alternative approach that can accelerate the oil palm breeding program. The SNP (single nucleotide polymorphism) genome-wide approach was then used to study the association between 18 phenotypes of bunch component in oil palm germplasm of E. oleifera from Suriname and Brazil Coari, some interspecific hybrids and some elite progeny of E. guineensis. The genotyping by sequencing (GBS) analysis produced a total of 459 million or approximately 798 thousand reads per sample and 3,252 SNPs were eligible for 456 genotypes. Using various association models, eleven normalized phenotypic data showed significant associations with 29 SNPs. Based on the annotations, 17 SNPs were related to genes wtih certain biological functions. Three SNPs were found to be at the exon of a gene, namely SNP4416, SNP349 and SNP3865, while the other 15 SNPs were at the intragenic to a gene. Four SNPs are common SNPs in phenotypes C16:0 and C18:1 as weel as in C20 0 and C20:1. This research shows the potential of SNPs that can be used as an alternative approach to E. oleifera backcross breeding, although further research is needed for validation purposes.

Transesterificación de aceite de palma (Elaeis guineensis x Elaeis oleífera) empleando catalizadores ácidos heterogéneos y agitación ultrasónica

En este estudio se reportan los resultados de la transesterificación del aceite de palma (Elaeis guineensis x Elaeis oleífera) utilizando catalizadores ácidos heterogéneos como la zirconia sulfatada (ZS), óxido de grafeno lfonado (OGrS), Amberlyst 15 (A15) y zeolita beta (Zβ)ueron caracterizados mediante el uso de difracción de rayos X, área superficial, y acidez de Brønsted - Lewis. Se evaluaron parámetros de reacción tales como: temperatura, tiempo de reacción, el porcentaje en peso de carga de catalizador y la relación molar de aceite metanol para la producción de biodiesel. Adicionalmente, se comparó la agitación mecánica y la ultrasónicadonde la segunda fue el medio de agitación más eficiente. Los mejores porcentajes de rendimiento de reacción fueron obtenidos empleando 40ºC de temperatura, 4 horas de reacción, 3% en peso del catalizador respecto al volumen total de la mezcla, una relación molar 1:30 de aceite de palma: metanol y agitación ultrasónica. En cuanto a la estabilidad de los catalizadores, se evaluó el rendimiento de la reacción con la reutilización, en donde los sólidos ZS y OGrS disminuyeron 8 % y 35 %, mientras que con A15 y Zβ, se redujo a 25 % y 5 % respectivamente.

The development of unlabeled probes-high resolution melting (UP-HRM) marker on SAD, IAA27 and ACC genes of oil palm

Saputra TI, Roberdi, Nugroho YA, Artutiningsih W, Purba OS, Maryanto SD, Yono D, Utomo C, Liwang T. 2021. The development of unlabeled probes-high resolution melting (UP-HRM) marker on SAD, IAA27 and ACC genes of oil palm. Biodiversitas 22: 3356-3362. The unlabeled probes-high resolution melting (UP-HRM) marker is a useful tool for detecting of single nucleotide polymorphisms (SNPs). The objectives of this study were to develop UP-HRM markers to differentiate specific SNPs patterns on oil palm. The marker was developed and tested with Elaeis guineensis (Eg), Elaeis oleifera (Eo), Eo x Eg (hybrid), and was validated with 53 individuals of BC1F1 populations ((Eo x Eg) x Eg). Four UP-HRM markers were developed based on 2 SNPs in the stearoyl-acyl-carrier-protein 9-desaturase (EgSAD), 1 SNP in the auxin-responsive protein IAA27-like (EgIAA27), and 1 SNP in the 1-amino cyclopropane-1-carboxylate oxidase (EgACC) genes. The SNP discovery result showed that Eg was represented a reference homozygote genotype, while Eo was represented as an alternative homozygote genotype and the Eo x Eg hybrid was represented as a heterozygote genotype in all genes. The typical UP-HRM melt curve graph was successfully generated. This result was consistent with each genotype model for all four markers. The UP-HRM markers can distinguish each genotype according to the single-pass sequencing results. Furthermore, dendrogram analysis on validation divided 53 BC1F1 samples into three cluster groups.

High-Oleic Palm Oil (HOPO) Production from Parthenocarpic Fruits in Oil Palm Interspecific Hybrids Using Naphthalene Acetic Acid

Interspecific OxG hybrids of African palm Elaeis guineensis Jacq. and the American palm Elaeis oleifera Cortes produce high-oleic palm oil (HOPO) with low saturated fatty acid content. OxG hybrids are highly productive, grow slowly, and are resistant to bud rot disease. However, OxG hybrid pollen presents low viability and germinability, so assisted pollination is a must. Hybrids can produce parthenocarpic or seedless fruits, with the exogenous application of plant growth regulators. Thus, naphthalene acetic acid (NAA) effects on parthenocarpic fruits induction, bunch formation, and oil quality were evaluated. The OxG hybrid Coari x La Mé was used. NAA doses, frequency, number of applications, and the phenological stages for the treatments were defined. A total dose of 1200 mg L−1 NAA applied three or four times produced bunches with better fruit set, similar average bunch weight, and oil to dry mesocarp than those obtained with assisted pollination. At a semi-commercial scale, 1200 mg L−1 NAA induced bunches that consisted of 93% or more of seedless fruits. Bunch number (2208 ± 84 versus 1690 ± 129) and oil to bunch (32.2 ± 0.7 versus 25.3 ± 0.8) were higher in the NAA induced bunches than in the assisted pollination. However, the average bunch weight was lower (12.2 ± 0.4 versus 14.9 ± 0.6). NAA increased oil to bunch in 36% (8.7 ± 0.1 versus 6.4 ± 0.3). Thus, with this technology, it is plausible to reach more than 10 tons per hectare per year of HOPO. Potentially, without increasing the planted oil palm area, OxG hybrids and NAA applications could alone meet the world’s fats and oil demands.