Judul: Agrobacterium tumefaciens-mediated transformation techniques in several plants
Abstrak: Genetic transformation is a process to introduce foreign gene from one organism to other organisms. This process is a site directed mutagenesis that can improve a good character without changing the existing characters. The use of Agrobacterium tumefaciens as a vector in genetic transformation has several advantages compared to other transformation techniques. It is a simple method, does not need special equipment, and produces high transformation efficiency in transfering a single copy of insert gene. This research is a comparative genetic transformation among several plants that have different characters. They are mangosteen as an apomixis plant, tobacco as a model plant, orchid as a monocotyledon plant, and coffee as a dicotyledon plant. The transformation were conducted in a same method and continued with regeneration step in antibiotic selectable medium. Gene insert confirmation using Polimerase Chain Reaction (PCR) technique showed that only tobacco the expected gene insert. The result suggested that the plant ability to grow in selective medium was not guaranteed as a transgenic plant before being confirmed using molecular assay approach. Some optimation in explants sterilization, infection techniques, number of transformed explants and tested transformed samples are required to be increases to achieve high transformation efficiency. Keyword : Agrobacterium tumefaciens-mediated transformation, transgenic plant.
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Judul: Perakitan Melastoma malabathricum Transgenik
Abstrak: Melastoma malabathricum is tolerant plant to acid and aluminum stresses, so this plant can be used as plant model for testing genes associated with tolerance to acid and Al. To test the role of genes, the method of genetic transformation of this plant has to be established. Therefore, this research had an objective to obtain the method of genetic transformation of M. malabathricum mediated by Agrobacterium tumefaciens. Genetic transformation of M. malabathricum had been done by using two strains of A. tumefaciens, i.e. C58C1 and EHA101, carrying a binary plasmid containing nptII (kanamycin resistance gene), as a selectable marker, and gusA (β-glucuronidase) as a reporter. The result of this research showed that C58C1 strain was more efficient than EHA101 for genetic transformation of M. malabathricum. Genetic transformation with C58C1 resulted three transgenic M. malabathricum plants tolerant to 100 mg/L kanamycine. The gus expression analysis showed that one transgenic plant expressed gus gene in the leave tissue. In addition, the node was better as plant material than leave disc for plant regeneration of genetic transformation proces.
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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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