Judul: Introduksi gen Hd3a ke dalam tanaman kentang (Solanum tuberosum L.) Kultivar Diamant
Abstrak: Hd3a gene encoded a protein inducing flowering and tuber formation in potato cultivar Andigena. This research has an objective to introduce the Hd3a gene into potato (Solanum tuberosum L.) cultivar Diamant under control of promoter rolC. Potato plants were propagated in vitro on MS2 macro medium. Genetic transformation was carried out by co-cultivation method by using Agrobacterium tumefaciens LBA4404. Internodes were used as explants for transformation. Selection of transgenic plants was performed in MS medium containing 10-40 mg/L hygromycin. The results showed that the average of transformation efficiency was 22.53% and regeneration efficiency of the calli was 100%. Transformation of 18 explants resulted 9 putative transgenic shoots and the regeneration rate was 2.33 putative transgenic shoots per callus. Transformation efficiency was affected by plant genotype, acetosyringone concentration, and technical factors such as washing and pincetting during the transformation process.
Keyword: Bogor Agricultural University (IPB), Solanum tuberosum L.., Hd3a gene, genetic transformation, cultivar Diamant, Agrobacterium tumefaciens

Judul: Transformasi Genetik Kentang (Solanum tuberosum L.) Kultivar Agria dengan Gen Pembungaan Hd3a
Abstrak: Potato is an important vegetables commodity in Indonesia. Agria has a potential cultivar to be used as french fries material. Flowering induction of this cultivar is very important to use this cultivar as a parent in the crossing with other cultivar. The aim of this research was to transform genetically potato cultivar Agria with Hd3a flowering gene controlled by rolC promoter. Potato plants were propagated in vitro on MS2 macro medium. Genetic transformation was carried out by co-cultivation method by using Agrobacterium tumefaciens. Putative transgenic calli and shorts were selected in MS and MS2 macro media respectively containing 10-20 mg/L hygromycin. The results showed that the transformation efficiency was 5.01% with regeneration efficiency relatively high 100%. Putative transgenic shoot regeneration per calli was one. Putative transgenic plants produced tuber in MS2 macro media whereas all non-transgenic plants did not. This result indicated that Hd3a induced formation of tuber of putative transgenic potato cultivar Agria.
Keyword: Bogor Agricultural University (IPB), Solanum tuberosum L., Hd3a flowering gene, genetic transformation, cultivar Agria

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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