Judul: Identifikasi Variasi Basa Nukleotida Gen Ketahanan Penyakit Blas Pi33 pada Galur Padi Terseleksi
Abstrak: Rice is one of the most important crops for human beings, thus increasing productivity are continually persecuted. Blast disease can reduce the rate of productivity of rice cultivation. Therefore, the forming programme of blast disease-resistant varieties needs to do effectively. One of broad-spectrum blast disease-resistant gene is Pi33. This study aims to identify the variation in the sequence of nucleotide bases of Pi33 gene in five interspesific strains which derived from Bio46 (IR64/Oryza rufipogon and CT13432). After isolated, DNA of five strains amplified used spesific primer for Pi33, G1010. Amplification result purified through Exo1SAP protocol. Labelling using fluorescent dyes done before sequencing nucleotide base using CEQ8000 instrument. The results showed that strains number 28 has introgesion of the three control its parent genome (subspecies of indica, subspecies of japonica, and O.rufipogon) while the strains number 79, 136, and 143 identical to indica genome, then number 195 strain identical to japonica genome. The result of ortholog analysis found conserved nucleotide base sequence, namely: CAGCAGCC which involved into heterotrimeric G-protein group. This protein has role as plant receptor for recognizing pathogen elicitor in interaction of rice and blast pathogen
Keyword: 

Judul: Blast Resistance Test On 51 Rice Strains Against Blast Disease (Pyricularia oryzae) race 173.
Abstrak: Padi hasil persilangan program pemuliaan padi Departemen Agronomi dan Hortikultura IPB sebanyak 51 galur telah berhasil diuji dengan menggunakan metode injeksi. Pengujian tanaman dilakukan dengan dua kali penapisan, penapisan I sebanyak tiga ulangan dan penapisan II sebanyak dua ulangan. Penapisan I dimulai dengan memproduksi spora Pyricularia oryzae di media oatmeal agar kemudian dicuci dengan akuades steril setelah diinkubasi selama 10 hari. Penyinaran n-UV dilakukan untuk menginduksi spora sehingga spora dapat dipanen. Suspensi spora dengan konsentrasi 105 – 106 spora/ml diinjeksi pada daun tanaman padi yang berumur 20 hari (± 4-5 daun). Penapisan II dilakukan untuk menguji 18 galur padi hasil penapisan I dengan tingkat ketahanan >90%. Sebanyak 7 galur diperoleh dari hasil penapisan I dan penapisan II dengan tingkat ketahanan 100% yaitu IPB107-F-5-1, IPB107-F-7-3, IPB113-F-2-2, IPB117-F-7-2, IPB140-F-2-1, IPB149-F-4, dan IPB149-F-8. Identifikasi gen ketahanan Pi-ta dilakukan dengan Polymerase chain reaction (PCR) menggunakan 2 pasang primer yaitu primer ekson1 yang mengamplifikasi daerah ekson 1 dan primer ekson2 yang mengamplifikasi daerah ekson 2 pada gen ketahanan Pi-ta. Hasil identifikasi didapatkan bahwa semua galur yang tahan mempunyai gen Pi-ta, termasuk kontrol peka (Kencana Bali). Hasil yang diperoleh berbeda dengan penelitian sebelumnya yang menunjukkan bahwa Kencana Bali tidak memiliki gen ketahanan Pi-ta. Hal tersebut diduga bahwa varietas Kencana Bali mengalami delesi pada bagian belakang ekson2. Kata kunci : galur padi, penyakit blas (Pyricularia oryzae), gen Pi-ta
Keyword: 

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.
Keyword: