Judul: Induksi Embrio Globular pada Tanaman Aren (Arenga pinnata (Wurmb) Merr.)
Abstrak: Sugar palm is a monocot plant belong to the Arecaceae family economically valuable and have bright prospects to be developed for food products to bio-ethanol substituting fossil fuels. This plant is usually propagated generatively yet there are a few issues being faced such as a long reproductive cycle, long seed production and dormancy, low germination capacity, and uniform seedling growth. Non-conventional plant breeding through biotechnology is the best possible alternative solution to provide good quality seedlings in order to increase sugar palm productivity. Tissue culture through somatic embryogenesis method is a technique that can be used to induce abundant and relatively uniform somatic embryos from zygotic embryos. One of the key factors when using this method which is focused in this research is the role of plant growth regulators under the auxin, cytokinin, and gibberellin groups. The objective of this study was to get the best media to produce somatic embryos from zygotic embryos of sugar palm. The obtained results are expected to be used for future sugar palm non-conventional breeding. This research was conducted at Tissue Culture Laboratory Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University from October 2012 to April 2013. It covers the embryogenic callus induction phase, globular embryo induction phase and globular embryos maturation phase. The first phase consisted six treatments with 2,4-D, NAA, and biotin combination aiming to induce callus formation from young zygotic embryos. In the second phase, callus obtained from the first phase were subcultured to 14 different treatments with various kinetin and TIBA combination. As for the third phase, explants which were obtained from the second phase were subcultured into media with or without GA3 combination. The variables which were observed were percentage and total sterile explants, percentage and total explants which induced callus formation, average percentage of callus coverage, percentage and total explants with base apocol smaller than haustorium, percentage and total pseudo roots, percentage and total explants which induced globular embryos, percentage and total alive and mature globular embryo clumps. Sterilization using NaOCl 1.575 % and alcohol 96 % was able to provide 50-85 % sterile explants. During callus induction phase, embryogenic callus were mostly formed at treatment A5 (MS + 3 mg l-1 2,4-D + 0.2 mg l-1 NAA + 100 mg l-1 biotin) which is 73.4 % after 8 weeks. All explants were able to form globular embryos on media B3 (callus A1 to media MS + 4 mg l-1 Kinetin), B6 (callus A1 to media MS + 1 mg l-1 Kinetin + 0.1 mg l-1 TIBA), B12 (callus A2 to media MS + 0.1 mg l-1 Kinetin + 1 mg l-1 TIBA), and B14 (callus A2 to media MS + 1 mg l-1 Kinetin + 1 mg l-1 TIBA) at 2 WAT during embryo globular induction phase. During embryo globular maturation phase, media C11 (globular embryo clumps B9 to media MS + 0.1 mg l-1 GA3) was able to induce 70.8 % mature globular embryo clumps.
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Judul: Embryo rescue secara in vitro dan produksi bibit aren (Arenga pinnata (Wurmb) Merr.).
Abstrak: Sugar palm is a member of Arecaceae (palmaceae) originated from Indo- Malayan archipelago. Sugar palm may have important position as biofuel producing crop. Hence, research and development of sugar palm need to be done. Availability of planting material is one of significant constraints to develop sugar palm for cultivation and breeding program. The main constraints of planting material (sugar palm seedlings) in Indonesia are the seed dormancy and the use of physiologically mature seed as planting material. Embryo rescue technique can be applied as a breakthrough to obtain sugar palm seedlings in a relatively short time. The objectives of the experiment were to evaluate: 1) the effect of zygotic embryo age and basal medium composition on germination and development of rescued zygotic embryo of sugar palm, 2) the effect of pre-treatment and cytokinins and 3) the effect of PGR combination (auxin with or without cytokinin) in vitro embryo culture and seedlings production of sugar palm. In exp. 1, zygotic embryos isolated from immature and mature sugar palm fruit were cultured on Y3 or WPM medium without of plant growth regulators. In exp. 2. sub-unit 1, immature zygotic embryos with or without pre-treatment were cultured onto Y3 medium containing cytokinin in the form of coconut water (100, 150 and 200 ml/l) or BAP (5 ppm). In exp. 2. sub-unit 2, addition of NAA (1 or 5 ppm), kinetin (5 ppm), BAP (5 ppm), a combination of NAA (1 or 5 ppm)+kinetin (5 ppm), or NAA (1 or 5 ppm)+BAP (5 ppm) in Y3 medium for plantlet regeneration. The result showed that the viability and germination of immature zygotic embryo (92%) was better than the mature one (72%). On the other hand, the composition of the basal medium (Y3 or WPM) did not significantly affect embryo germination. Some of the culture zygotic embryo developed abnormal development of haustorium and cotyledonary petiole, at 32% and 26%, respectively. The percentage of planlets from zygotic embryo in this experiment range from 6%-25%. The results showed that cytokinin (coconut water or BAP) did not affect growth of the rescued zygotic embryo, whereas immature embryo with pretreatment led to the highest shoot and root formations, respectively. On the other hand, addition of PGR (auxin with or without cytokinin) showed positive effects on length of root from the zygotic embryos. A combination of NAA (5 ppm)+BAP (5 ppm) gave the highest number planlets. The plantlet of sugar palm were successfully regenerated from rescued embryos and transferred into soil.
Keyword: auxin, coconut water, cytokinin, embryo rescue and sugar palm

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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