Judul: Amplifikasi Gen Bar dan Gen Hpt Terkait Stabilitas Padi Mutan Serta Evaluasi Karakter Agronominya
Abstrak: Transposon Ac / Ds system containing an activation tagging constructs serves to develop a mutant plant that will produce changes in phenotype. This study aims to amplify the bar and hpt genes related to the stability of the mutant rice transposon Ac/Ds and observe the changes in phenotype based on the agronomy characters. Rice plant materials used for the study were six mutant T2 rice lines IR.64 (total 214 plants) and IR64 wild type rice as a control. The DNA of mutant plants was isolated and then amplified by PCR technique using primers specific for the bar and hpt genes. The results showed that the bar and hpt genes in the rice plant IR.64 mutant T2 with size were ± 700 bp and ± 600 bp. Evaluation of agronomic characters showed there were changes in these characters of mutant rice lines IR64 generation T2 that probably caused by the transposon insertion element containing 4x enhancer.
Keyword: Bogor Agricultural University (IPB), IR64., agronomic traits, Ac / Ds transposon

Judul: Analisis Molekuler dan Fenotipe Galur Padi Transgenik IR64 Generasi T3 yang Mengandung Penanda Aktivasi untuk Toleransi Kekeringan
Abstrak: Activation tagging transgenic rice cv. IR64 had been developed by introducing a construct of activation tagging transposon Ac/Ds. Phenotipic character associated with drought stress tolerance of the transgenic rice lines have not been analyzed. This study aimed to evaluate T3 generation of activation tagging transgenic rice lines cv. IR64 to drought stress treatment. The methodology of study consisted of several steps including germination of samples seeds, screening the seedling with drought strees treatment, molecular analysis of the rice lines identify hpt and bar genes, and observation of agronomic character. Results of study showed that there were 34 out of 84 plants that tolerant to drought stress. A total of 23 plants of tolerant plants were detected carrying only bar gene after PCR analysis and indicated that the plants were stable mutants. Generaly, compared to the non-transgenic plants, there were changes in several agronomic parameters of transgenic rice plants cv. IR64 T3 generation. A total of nine plants increased of its height, six plants had a faster harvesting time, and 21 plants had higher weight of 100 seeds compared by non-transgenic plants.
Keyword: Bogor Agricultural University (IPB), drought stress tolerance, activation tagged, Rice (Oryza sativa L.)

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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