Category Archives: 1995 Vol 7 No 1

Long-term in vitro maintenance of oil palm (Elaeis guineensis Jacq.) clones through axenic root culture

Studies were carried out to determine whether oil palm clones could be maintained long-term in vitro by means of root cultures. It was found that isolated root explants excised from axenic ramets could be maintained in culture for at least 18 months by repeated subculture. Root explants 3 cm in length produced more axillary roots than 1 cm root explants.

A full strength modified MS medium supported root tip elongation and production of axillary roots better than a half strength nutrient medium. Root explants with root tips (RT) mutiplied by root tip elongation and production of axillary roots whilst roots devoid of root tips (RS) multiplied by production of axillary roots only. Root tip segments (RT) sustained growth better than RS segments during subculturing, but there was a decline in the growth vigour of the new explants in the subsequent subcultures.

Biochemical studies on abnormal clones of the oil palm (Elaeis guineensis)

A preliminary study was conducted on the biochemistry of oil palm clones producing mantled fruits. The kernels, mesocarp, leaves and callus tissues derived from both normal palms and those with mantled fruits were analysed. The results showed that the mantled material seemed to have a higher level of reducing sugars, particularly in the kernels and the callus tissues. The difference in the reducing sugar content of leaf extracts from normal palms and those producing mantled fruits was not highly significant except in the P38 clone. The content of soluble protein and ethanol-soluble nitrogenous compounds appeared inconsistent between different batches of leaf samples though there was generally an increasing trend in material from palms producing mantled fruits. No differences were observed between the activities of polyphenol oxidases, esterases or peroxidases in the leaf extracts from normal palms and those with mantled fruits. Analyses of total amino acids in the mesocarp tissues of mantled fruit from clones P10, P12, P15 and P38 showed that there was an increase in serine content but a decrease in amino acids related to apartate.

Life history and feeding behaviour of the oil palm bagworm, Metisa plana Walker

Bagworms were reared in a controlled environment room (CER) to obtain details of their life history. Eggs were pale yellow and barrel-shaped, and their incubation period was 19.7 ± 0.3 days. Fecundity of laboratory-reared females was higher than that of wild-caught females (158.3 ± 10.3 vs 99.9 ± 5.7 eggs/ female) yet lower than those recorded for several other species of Psychidae. Fertility was high (generally > 90%). Sexual dimorphism in instar number was recorded (5-6 for males vs 6-7 for females). Head capsule widths, bag lengths and morphology can be used to determine instars. Most leaf tissue removed from oil palm foliage (66.8%) was used for maintenance and body growth, and the remainder for bag construction. Larvae preferred upper leaf surface for feeding and lower surface for resting and moulting. Sexual dimorphism was also noted in pupal size (males smaller than females) and developmental time (males, 21.4 ± 0.3 days; females, 10.0 ± 0.4 days). Total developmental times of males and females did not differ, suggesting that overlapping generations are not a requisite for an outbreak. Sex ratio was male biased (8.5:1).

Colombia’s national tree : The wax palm Ceroxylon quindiuense and its relatives

A review of the nineteenth-century literature on the wax palms of the genus Ceroxylon is presented, together with the available information on the biology, systematics, economic uses, ornamental value, and conservation status of the species in this genus. The wax palms of the genus Ceroxylon are spectacular representatives of the palm family, Palmae. They grow at altitudes up to 3150 m, often in populations of hundreds of thousands of individuals, and their trunks reach 60 m in height. Travellers and naturalist, who for the last 200 years have visited the wax palm forests on the steep slopes of the Colombian central Andes, have admired their magnificence and referred to them extensively in their writings. Known as a source of an excellent wax, these palms have attracted the attention of chemists and industrialists alike. The genus Ceroxylon comprises eleven species distributed throughout the northern Andes from Venezuela to Bolivia. The genus is a member of a small, relatively ancient lineage, and its species are widely scattered throughout the southern hemisphere. The tallest and most populous species of wax palms, the Quindio wax palm Ceroxylon quindiuense (Karsten) Wendland, has been adopted as Colombia’s national tree and is now protected by law. However Ceroxylon quindiuense and other species of wax palms are threatened with extinction due to disturbance of their natural habitats, which interrupts their life cycles and increases their susceptibility to attack by pathogens. We here present an up-to-date review of the literature on wax palms. Although the bibliography may appear extensive, the great majority of these references date from the nineteenth century and are mainly of historical interest. After almost two centuries, from the introduction of the wax palms to western science and their great admiration by naturalists, very little has been published about the basic biology of these palms. We hope this will soon change, for any effort to conserve these species will have to be based upon detailed knowledge of their biology.

Cloning date palm (Phoenix dactylifera L.) DNA and characterization of low, medium, and high copy DNA sequences

Total DNA was extracted from mature leaves of the date palm (Phoenix dactylifera L.) cultivator ‘Bou-Sthammi Noire’. The DNA was digested with Pst1 and the fragments shotgun-cloned in E-coli DH5 alpha using the plasmid vector pUC19. A total of 124 clones were characterized by dot blot hybridization using 32P labelled genomic DNA as the probe. 74% of the isolates contained single copy sequences. Many of the cloned fragments (58%) were less than 900 bp. Some of the single copy clones, when used as probes in Southern blot analysis of DNA extracted from twelve Moroccan date palm cultivars, detected restriction fragment length polymorphisms. The construction and the availability of a genomic library opens up the possibility of obtaining a panel of potentially interesting genomic DNA clones for initiating RFLP studies on breeding line of Moroccan date palms in order to speed up the selection and breeding of Bayoud resistant palms in Morocco.

Clarity and chemical composition of palm olein-sunflower and palm olein-safflower oil blends

Double fractionated palm olein samples of iodine value (IV) 60 (DfPOo IV 60) and IV 65 (DfPOo IV 65) were blended with sunflower oil (SFO) and high-oleic safflower oil (SAFO) in various proportions. The clarity of the blends was determined after storage at various temperatures. The maximum levels of DfPOo IV 65 that could be mixed with SFO and SAFO to give blends that remained clear for at least 240 days at 20 degrees C were 60% and 70% respectively. With DfPOo IV 60, the levels were 30% and 60% respectively. At 15 degrees C, with both SFO and SAFO the maximum levels were 20% with DfPOo IV 60 and 30% with DfPOo IV 65. At 10 degrees C, all blends containing 20% palm olein except DfPOo IV 60 -SFO and SAFO 20;80 remained clear for about 180 days. At 5 degrees C blends containing 10% palm olein and 90% SFO remained clear for 90 days. Blends of either SFO or SAFO with, up to 20% DfPOo IV 60 or 30% DfPOo IV 65 passed the cold test. Blending of SFO or SAFO with DfPOo improved the fatty acid composition in terms of the saturated; monosaturated; polyunsaturated ratio.

Evolution of palm oil trade policy in Indonesia, 1978-1991

This article traces the evolution of Indonesia’s palm oil trade policies. Special attention is given to the ten years spanning 1978-1987 when the overriding emphasis of palm oil trade policy was on securing domestic supplies and stabilizing prices of edible oils. That period was followed by a transition toward policies to promote palm oil exports culminating in complete export deregulation in June 1991. The shift in focus of policy from domestic procurement and price stabilization toward export promotion that began in December 1987 was part of a broader move toward deregulation in Indonesia going back to about 1983. For palm oil, rapid growth in domestic production was a driving force in deregulation. Expanding production elicited a shift from restrictions on domestic and international trade arising from concern about shortfalls in meeting domestic needs to freer trade to avoid accumulation of surpluses. Decisive, too, was the realization that export restrictions offered little (if any) protection to Indonesian consumers.

Occurrence of trunk rot in some oleifera backcrosses

Several (dura x oleifera) x dura backcrosses planted in August 1982 at Pusat Perkhidmatan Pertanian Tun Razak (PPPTR) in Pahang were found to show a high incidence of trunk rot in January 1991. This short communication is to document the occurence of trunk rot in oleifera backcrosses, a phenomenon which has not been reported before. The backcrosses originated from crossing the hybrids of Deli dura of SOCFIN origin and the Kuala Lumpur Melanococca (KLM), an oleifera palm believed to be of brazilian origin (Ooi et al., 1981), with Deli duras of Serdang and Ulu Remis origins, i.e (DxO) x D.