Judul: Effect of Genotype and Putrescine on Androgenesis of Eggplant  (Solanum melongena L.) on Solid Media In Vitro
Abstrak: Kultur antera dapat mempercepat perolehan galur murni untuk program pemuliaan tanaman. Namun, metode kultur antera terong dengan efisiensi tinggi belum diperoleh. Genotipe memiliki pengaruh yang besar terhadap keberhasilan androgenesis terong. Penambahan putresin ke kultur antera dapat meningkatkan jumlah kalus, jumlah embrio, dan jumlah tanaman yang diregenerasikan. Tujuan penelitian ini ialah untuk mendapatkan genotipe dan konsentrasi putresin yang optimal pada media induksi kultur antera terong. Bahan yang digunakan ialah kuncup bunga terong dari tanaman yang dibudidayakan di rumah kaca. Kultur antera dilakukan dalam tiga tahap percobaan: induksi embrio, perkecambahan embrio, dan regenerasi tanaman. Percobaan induksi embrio dilakukan dengan 10 ulangan menggunakan Rancangan Acak Lengkap (RAL) dengan dua faktor (genotipe dan putresin). Faktor genotipe terdiri atas tiga taraf (Pertiwi, Provita, dan Edlyn). Faktor putresin terdiri atas tiga taraf konsentrasi (0 mM, 1 mM, dan 3 mM). Antera yang berhasil diinduksi menjadi embrio disubkultur pada media kecambah selama 2 minggu, dan kecambah kemudian disubkultur pada media perakaran untuk diregenerasi. Hasil penelitian menunjukkan bahwa genotipe Edlyn menghasilkan embrio paling banyak, tetapi tidak berbeda nyata dengan genotipe Provita. Putresin 1 mM menghasilkan embrio paling banyak yang berbeda nyata dengan putresin 0 mM dan putresin 3 mM. Efisiensi kultur antera terbaik adalah genotipe Edlyn dengan konsentrasi putresin 1 mM. Tidak terdapat interaksi antara genotipe dan putresin pada semua peubah, kecuali pada antera menghasilkan kalus dan waktu muncul embrio., Anther culture can accelerate the acquisition of pure lines for plant breeding programs. However, eggplant anther culture media with high efficiency has not been obtained. Genotype has a great influence on the success of eggplant androgenesis. The addition of putrescine to anther culture media can increase the number of calluses, the number of embryos, and the number of plants. The purpose of this study was to obtain the optimal genotype and concentration of putrescine in eggplant anther culture. The material used was obtained from eggplant flower buds of plants cultivated in a greenhouse. Anther culture was carried out in three experimental stages: embryo induction, embryo germination, and plant regeneration. The embryo induction experiment was carried out with 10 replications using a completely randomized design (CRD) with two factors (genotype and putrescine). The genotype factor consisted of three levels (Pertiwi, Provita, and Edlyn). Putrescine factor consisted of three concentration levels (0 mM, 1 mM, and 3 mM). Anthers that were successfully induced into embryos were subcultured to germination media for 2 weeks, and the germinated embryo were then subcultured to rooting media. The results showed that Edlyn produced the highest number of embryos, but it was not significantly different from the Provita. Putrescine 1 mM produced the highest number of embryos which was significantly different from putrescine 0 mM and putrescine 3 mM. The best anther culture efficiency was obtained in Edlyn genotype with a putrescine concentration of 1 mM. There was no interaction between genotype and putrescine in all variables, except in the anthers producing callus and embryo emergence time.
Keyword: anther culture, eggplant, embryogenesis, putrescine, variety

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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