Judul: Ethyl Methane Sulphonate Treatment Mutation Induction on Anther Cultures of Hot Pepper (Capsicum annuum L.) and Its Effect on Embryogenesis Capacity
Abstrak: Metode kultur antera yang efisien pada sistem media dua lapis telah dikembangkan untuk memproduksi tanaman haploid ganda (HG) cabai kultivar lokal Indonesia (Capsicum annuum L.). Untuk percepatan dalam menghasilkan variasi genetik dan perbaikan sifat dari cabai, metode kultur antera ini dikombinasikan dengan teknik mutagenesis dalam penelitian ini. Induksi mutasi dilakukan melalui perendaman antera sebagai sumber eksplan pada larutan etil metan sulfonat (EMS) konsentrasi 0.1% dan 0.5% selama 1, 3, dan 6 jam sebelum kultur. Perlakuan EMS 0.1% selama 6 jam tidak hanya dapat menginduksi mutasi, tetapi juga meningkatkan respon embriogenesis, rata-rata embrio lengkap, dan rata-rata embrio berkecambah. Mutasi yang terjadi dapat dideteksi pada tanaman yang berasal dari kultur antera pada sifat morfologi daun dan batang, serta isozim peroksidase, aspartat aminotransferase, dan esterase. Metode kultur antera yang dikombinasikan dengan teknik mutagenesis ini dapat digunakan untuk mempercepat proses pemuliaan tanaman cabai kultivar lokal Indonesia.
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Judul: Responsivitas dan Kapasitas Androgenesis Beberapa Genotipe Cabai dan Terong dalam Kultur Antera pada Media Dua-Lapis
Abstrak: Productivity of hot pepper (Capsicum annuum L) and eggplant (Solanum melongena L) can be improved through the use of good quality seeds, such as hybrid seeds. Development of hybrid seed requires parental in the form of a pure lines, which is can be produced quickly using anther culture. The purpose of the study was to test the application of anther culture technique with a double-layered medium system that has been developed in hot pepper (pepper method) and tobacco (tobacco method) for several genotypes of hot pepper and eggplant. A double-layered medium system was culturing anther in liquid medium above the solid medium and incubated under certain condition. The result was that the pepper method successfully induced androgenesis for three types of plant that were all genotypes of pepper, eggplant var Antaboga, and tobacco SR1, while tobacco method was only successful for tobacco SR1. Androgenic responsiveness for genotypes tested was big hot pepper var Tombak (77 %), China big hot pepper (67 %), curly type-1 hot pepper (21 %), curly type-2 hot pepper (10 %), and eggplant var Antaboga (7 %). The result of total embryos per bud for each genotype of pepper was 5.7, 1.7, 0.3, and 0.5, respectively. Total embryos for eggplant var Antaboga was 0.2 embryos per bud. The result of ploidy analysis at one anther culture derived plant for curly hot pepper was haploid and eggplant was mixoploid that both proved the androgenesis process. This method of anther culture with pepper method has the potential to be tested on other members of genus Solanum, such as tomato which still quite difficult to induce its androgenesis.
Keyword: Bogor Agricultural University (IPB), eggplant., tobacco, pepper, double-layered medium, anther culture

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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