Judul: Introduction Gene of Submergence-Tolerant (Sub1) on Ciherang Rice Varieties.
Abstrak: Upaya untuk meningkatkan produksi padi terus dilakukan seiring dengan bertambahnya penduduk dan meningkatnya kebutuhan beras. Perubahan iklim yang tidak menentu menuntut perlunya pengembangan padi yang toleran terhadap cekaman abiotik, seperti kekeringan, salinitas tinggi, maupun genangan. Hasil panen rendah dan resiko kegagalan tanam akibat banjir umum ditemui pada areal rawa pasang surut, rawa lebak, dan tepian sungai. Salah satu solusi yang berkelanjutan dan permanen adalah mengembangkan varietas dengan hasil tinggi yang toleran terhadap rendaman. Penelitian ini mengembangkan padi Ciherang toleran genangan yang dilakukan secara spesifik dengan metode persilangan terarah (site-directed crossing) untuk menghindari produk transgenik. Penelitian ini bertujuan memperoleh tanaman BC3F1 Ciherang-Sub1 hasil persilangan balik BC2F1 Ciherang-Sub1 dan Ciherang serta menyeleksi tanaman BC3F1 yang membawa gen Sub1 dengan menggunakan PCR. Hasil uji genangan diperoleh 13 tanaman BC3F1 yaitu 6 tanaman BC3F1 Ciherang/Swarna-Sub1 dan 7 tanaman BC3F1 Ciherang/IR64-Sub1. Hasil PCR dengan marka AEX1F dan AEX1R menunjukkan pita DNA untuk gen Sub1A yang berukuran 231 bp. Sedangkan hasil PCR dengan marka gabungan RM219F dan AEX1R dapat membedakan sifat heterozigot antara padi host Ciherang, donor Swarna-Sub1 dan IR64-Sub1, serta progeni BC3F1 Ciherang-Sub1 dengan tambahan pita yang menunjukkan penyisipan Sub1 dari donor ke dalam host.
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Judul: Aplikasi berbagai marka Sub1 (AEX1, SUB1C173, RM464A, RM 219) pada pembentukan dan seleksi F1 Ciherang toleran genangan.
Abstrak: Uncertain climate changes forced a tolerant rice abiotic stress, such as drought, high salinity, and submergence. Excessive rainfall often soak the rice fields which caused rice damage. Ciherang is a superior rice varieties that have a high productivity and resistance to some diseases. However, these rice varieties have a weakness that is sensitive submergence stress. Therefore, tolerant submergence rice varieties Ciherang is necessary to be developed. Rice which has a submergence tolerant gene (Submergence 1) has been known is donor-Sub1 rice (Swarna-Sub1 and IR64-Sub1). Insertion genes Sub1 from donor-Sub1 have done to Ciherang variety using site-directed crossing method. The objectives of this research’s were to build up and selecting F1 Ciherang-Sub1 rice plant that carried Sub1 gene with marker Sub1 using PCR technique. Result of this research showed that with the marker SUB1C173 obtained allele donor-Sub1 and F1 Ciherang-Sub1 sizes 108 bp and 126 bp. Results of selection using AEX1 marker obtained Sub1A allele with size 231 bp. RM219 marker can distinguish Ciherang’s host, Sub1- donor, and F1 Ciherang-Sub1 with DNA fragment sizes of 204 bp and 194 bp. But, RM464A marker cannot distinguish the difference of allele patterns from that three variety.
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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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