Aluminum (Al) will be toxic to plants when soil is very acid. Soil reaction on acid condition tends to turn Al into trivalent cation (Al 3+ ) disturbing the function of the root end cells in doing the division and elongating the function. Today, the study of Al stress on crop trees as oil palm is very little. This research was aimed to study the growth of oil palm varieties in growing media treated Al stress. The experiment was conducted in the screen house using a randomized block design with two treatments, oil palm varieties and concentrations of Al. Varieties consisted of five oil palm progenies (OPP) i.e. PPKS239, PPKS540, PPKS718, Simalungun, and Dumpy. They were planted into the sterile sand medium in the form of sprouts and Al was treated with five different concentrations, 0, 75, 150, 225, and 300 ppm. Al was applied at the same time in the plant from 4 to 12 weeks after planting. Observations were conducted on several morphological and physiological variables at shoots and roots. The results showed a significant interaction between varieties and Al on the length of primary roots and reducing sugar content. The average of reducing sugar content was 24% less from control than it was when treated by Al 300 ppm. Simalungun varieties had more tolerant to Al than others. The length of Simalungun primary roots was more stable when the concentration of Al was 300 ppm whereas PPKS718 and PPKS540 varieties were decreased 24.3 and 12.4% respectively. The tolerance of Simalungun was also marked from reducing sugar content which was lower than other varieties. According to Koch (2004) [1], the low content of reducing sugar when given Al was an indication of plant resistance mechanisms against Al toxicity where the number of sugar was transported from roots to the shoots for immobilizing Al. Consequently, it decreased sugar content in the shoot.

In the assumption of oil palm breeders, virescens oil palm type has no real economic value. Therefore, the nigrescens is more considered. However, the virescens gives a visual cue that fruits are ripe without waiting to detach. In 2010, Indonesian Oil Palm Research Institute (IOPRI) successfully planted an open-pollinated population of Cameroon oil palm. The population was characterized for virescens type frequency, as well as the bunch components, quantity and quality of crude palm oil. The virescens frequency per accession was sufficiently wide, ranging from 3.33-65.71%, and was affected by the parent type, nigrescens or virescens. Most of the virescens's fruit form is observed to be of dura, except one sample, which was observed to be tenera. The mesocarp to fruit (MF) and industrial extraction ratio (IER) percentage are similar to the nigrescens dura, namely 37.7% and 9.5%, respectively. Its oil quality is better than nigrescens, and it has total carotene ranging from 155-1246 ppm. The oleic fatty acid is higher than 50%, and the palmitic is lower than 40%. Due to the ease of determining mature fruits, as well as the higher oil quality, virescens oil palm type is recommended to be introgressed in a breeding program.

Background The development of basal stem rot (BSR) disease in oil palm is associated with lignin during vegetative growth and salicylic acid (SA) biosynthesis. The increase in the lignin content, SA accumulation, growth, and root biomass could indicate the resistance of oil palm seedlings to BSR disease. Therefore, although there are many studies on the interactions between the Ganoderma boninense and oil palm, research on evaluation of physiological processes, biochemistry, and molecules occurring during early internal symptoms of BSR in roots of oil palm (Elaeis guineensis Jacq.) are essential. Results Ganoderma boninense inoculation indicated that C01, C02, and C05 seedlings were susceptible, while the other three seedlings, C03, C07, and C08, were resistant based on Ganoderma Disease Index (GDI). Infection by G. boninense in the most susceptible seedlings C05 reduced fresh weight of roots (FW) by 9.0%, and lignin content by 10.9%. The most resistant seedlings C08 were reduced by only 8.4%, and 0.2% regarding their fresh weight and lignin content, respectively. BSR disease induced SA accumulation in the most susceptible C08 and decreased peroxidase (PRX) enzyme (EC 1.11.1.7) activities in root tissues of oil palm seedlings except C07 and C08 where PRX activities remained high in the 4 months after planting. Infection with G. boninense also increased glutathione S-transferase U19-like (EgGSTU19) gene expression in the root tissues of susceptible seedlings, while laccase-24 (EgLCC24) gene expression was associated with resistance against BSR disease. Based on the relative expression of twelve genes, two genes are categorized as receptors (EgWAKL5, EgMIK1), two genes as biosynthesis signal transduction compound (EgOPR5, EgACO1), five genes as defense responses (EgROMT, EgSOT12, EgLCC24, EgGLT3, EgGSTU19), and one gene as trans-resveratrol di-O-methyltransferase-like (EgRNaseIII) predicted related to BSR infection. While two other genes remain unknown (EgUnk1, EgUnk2). Conclusions Ganoderma infection-induced SA accumulation and lignification in resistant accessions promote the seedlings root biomass. Oil palm seedlings have a synergistic physical, biochemical, and molecular defense mechanism to the BSR disease. The utilization of nucleotide-based molecular markers using EgLCC24 gene is able to detect resistant oil palm seedlings to G. boninense.

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.

Penyimpanan plasma nutfah kelapa sawit dapat dilakukan dengan berbagai cara, salah satunya dengan metode kriopreservasi yang mampu menyimpan plasma nutfah dalam jangka waktu yang cukup lama. Kriopreservasi diartikan sebagai salah satu teknik penyimpanan jaringan tanaman menggunakan temperatur yang sangat rendah -1960C (ultra low) pada media kriogenik menggunakan nitrogen cair. Kriopreservasi terbagi menjadi 2 yaitu metode kriopreservasi klasik dan metode kriopreservasi baru. Pada kelapa sawit, metode kriopreservasi yang banyak digunakan yaitu menggunakan metode kriopreservasi klasik dan metode baru diantaranya vitrifikasi dan droplet-vitrifikasi. Material kelapa sawit yang disimpan diantaranya embrio zigotik, kernel, polen, kalus, suspensi sel dan sel embriogenik dari suspensi sel, dan embrio somatik. Dari berbagai jenis material tersebut, mayoritas menggunakan material berupa embrio somatik yang dihasilkan dari perbanyakan menggunakan kultur jaringan. Penggunaan embrio somatik dinilai lebih mudah dilakukan dan mampu menghasilkan pertumbuhan kembali setelah kriopreservasi dengan persentase keberhasilan yang cukup tinggi.