Judul: Rekayasa genetik pada tanaman kentang (Solanum tuberosum) kultivar Diamant dengan gen Hd3a dibawah kendali promoter 35SCaMV
Abstrak: Potato is one of important horticultural and food crops in Indonesia due to the high economic value. Flower has an important role in the conventional breeding to cross, so the induction of flowering is very important. In several species, Hd3a induced flowering. In potato cv. Andigena, Hd3a does not only induce the flowering, but also induces the tuber formation. This research has an objective to engineer genetically potato cv. Diamant with Hd3a under the control of the 35SCaMV promoter. Potato plants were propagated in vitro in MS2 macro media. Genetic transformation is done by using the internode fragments as explants intermediated by Agrobacterium tumefaciens with co-cultivation method. Calli and putative transgenic plants sere selected in MS media containing 10-40 mg/l hygromicin. The results showed that the average transformation efficiency was 38.88% with low regeneration efficiency, i.e. 9.5%. The average of shoots produced per callus was 2.25. At six weeks old, putative transgenic and non transgenic potato plants did not form a flower, but 10% of putative transgenic 3 plants formed a tuber and all non transgenic ones did not produce a tuber. This result indicates that Hd3a is capable to induce tuber formation. Six weeks is not enough time for flower formation.
Keyword: Bogor Agricultural University (IPB), Solanum tuberosum, Hd3a gene, genetic transformation, cv. Diamant, 35SCaMV

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: 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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