This study examines the fresh fruit bunch (FFB) yield and the effect of fruit storage on the quality of palm oil in Bangun Bandar Estate, Dolok Masihul, North Sumatra, with special

Multi-parental populations are promising tools for identifying quantitative disease resistance loci. Stem rot caused by Ganoderma boninense is a major threat to palm oil production, with yield losses of up to 80% prompting premature replantation of palms. There is evidence of genetic resistance sources, but the genetic architecture of Ganoderma resistance has not yet been investigated. This study aimed to identify Ganoderma resistance loci using an oil palm multi-parental population derived from nine major founders of ongoing breeding programs. A total of 1200 palm trees of the multi-parental population was planted in plots naturally infected by Ganoderma, and their health status was assessed biannually over 25 yr. The data were treated as survival data, and modeled using the Cox regression model, including a spatial effect to take the spatial component in the spread of Ganoderma into account. Based on the genotypes of 757 palm trees out of the 1200 planted, and on pedigree information, resistance loci were identified using a random effect with identity-by-descent kinship matrices as covariance matrices in the Cox model. Four Ganoderma resistance loci were identified, two controlling the occurrence of the first Ganoderma symptoms, and two the death of palm trees, while favorable haplotypes were identified among a major gene pool for ongoing breeding programs. This study implemented an efficient and flexible QTL mapping approach, and generated unique valuable information for the selection of oil palm varieties resistant to Ganoderma disease.

Observations of the vegetative and reproductive biomass produced annually and the mineral element contents have been conducted on diverse oil palm plant materials tested in a genetic test in Indonesia. The results show that the nutrient uptake (for trunk growth, leaf renewal and bunch export) greatly varies (CV = 10% for N uptake and 17% for K uptake) with the origins of the planting materials considered. For equivalent production, the uptake in nutrients of certain plant material may differ very significantly; for the same level of uptake in nutrients, production can vary significantly. This study supports the hypothesis that the optimal nutrient thresholds are intrinsically linked to the plant material. It assumes that some planting materials have different needs and that a fertilizer regime could be adapted to their specific needs without losses in performance. To confirm these assumptions, the need of implementing specific experimental devices with differentiated fertilization regimes is discussed. (Résumé d'auteur

Basyuni M, Wati R, Deni I, Tia AR, Slamet B, Siregar ES, Syahputra I. 2018. Cluster analysis of polyisoprenoid in oil palm(Elaeis guineensis) leaves in different land-uses to find the possible cause of yield gap from planting materials. Biodiversitas 19: 1492-1501. The distribution and occurrence of polyprenols and dolichols in the leaves of oil palm (Elaeis guineensis Jacq.) plantations indifferent land-uses in North Sumatra, Indonesia were analyzed using two-dimensional thin layer chromatography (2D-TLC). Eighty-oneof oil palm leaves were sampled to represent twenty-seven sites of land-uses, namely paddy field (four locations), mangrove (threelocations) in Lubuk Kertang, Langkat, North Sumatra. In addition, samples from four groups of smallholders in Stabat, Langkat, sixsites in Bangun Bandar, Serdang Bedagai, and ten sites on the campus of Universitas Sumatera Utara (USU), North Sumatra werecollected. In the leaves, only one type (type II) with respect to the distribution of polyisoprenoids was detected: having the presence ofboth polyprenols and dolichols. Either type I, having predominance of dolichols over polyprenols or type III, displaying dominatingpolyprenols over dolichols were not observed. Results also showed that chain-length distribution of ficaprenols (C50-C60) without longerpolyprenols (C85-C100) and dolichols of C85-C100 was detected in the paddy field, mangroves, and one site in USU campus. Thispolyisoprenoid profile was close to dura type of Elaeis guineensis. By contrast, the remaining land-uses had ficaprenols and longerpolyprenols, and dolichols (C85-C100), which belong to tenera or pisifera type. To confirm this finding, a dendrogram was constructed.Cluster analysis demonstrated that twenty-seven sites of E. guineensis were grouped into appropriate types of dura, pifiera, and teneraaccordingly, indicating that the existence of polyisoprenoids in E. guineensis was a chemotaxonomic marker. The finding ofpolyisoprenoid pattern of E. guineensis as dura type in mangrove and paddy field sites may reveal significant causes of yield gap in oilpalm plantation from planting materials.

Arifiyanto D, Basyuni M, Sumardi, Putri LAP, Siregar ES, Risnasari I, Syahputra I. 2017. Short Communication: Occurrence and cluster analysis of palm oil (Elaeis guineensis) fruit type using two-dimensional thin layer chromatography. Biodiversitas 18: 1487- 1492. The problems that have been faced by palm oil breeders are the length of time and high costs to discover the type of palm oil (Elaeis guineensis) fruit namely Dura, Pisifera, or Tenera, before using as a seed parent. These conditions are ineffective and add to the cost of maintenance and the production of seedling is more expensive. The present study describes the occurrence and cluster analysis of palm oil fruits using two-dimensional thin layer chromatography (2D-TLC). The leaves and fruit on each fruit mesocarp and shell, commercial seed on each fruit type were sampled through direct determination, plant nurseries, commercial seed and unknown type of palm oil. 2D-TLC chromatograms of hexane extracts showed diversity in palm oil fruits: Dura had ficaprenol-type polyprenol (C50-C60) and no carbon chain-length of polyprenol and dolichols (C85-C100) were found. In Tenera polyprenols of C45-C60 and C90-C100 occurred and dolichols of C85-C105 as well, where polyprenols of C45 and C105 and dolichol of C105 found in Tenera were not detected in Pisifera. To confirm these findings, cluster analysis was drawn using the UPGMA method. The dendrogram demonstrated that the three types of palm oil were grouped to fruit type, suggesting that the occurrence of polyisoprenoids in palm oil fruits were chemotaxonomically significant.