Judul: Evaluasi Galur-Galur Generasi Awal Sorgum (Sorghum Bicolor (L.) Moench) Hasil Persilangan B-69 × Numbu
Abstrak: Penelitian ini bertujuan untuk mengamati keragaan, keragaman antar galur dan keragaman dalam galur karakter agronomi dari galur-galur generasi awal F4 dan BC1F3 hasil persilangan B-69 × Numbu. Galur-galur dengan ragam dalam galur yang lebih rendah dari ragam antar galur akan dilanjutan ke generasi berikutnya. Penelitian ini dilaksanakan di Kebun Percobaan Leuwikopo, Institut Pertanian Bogor dari Februari sampai Mei 2014 dan di Laboratorium Pemuliaan Tanaman Departemen Agronomi dan Hortikultura dari Mei sampai Juni 2014. Penelitian ini menggunakan 32 galur F4, 13 galur BCP1F3, 22 galur BCP2F3 tanpa ulangan. Kedua tetua yaitu Numbu dan B-69 diulang sebanyak lima kali. Hasil dari penelitian adalah terdapat 33 galur yang dapat dilanjutkan ke generasi selanjutnya yaitu, 19 galur F4, 5 galur BC1P1F3, dan 9 galur BC1P2F3. Panjang malai memiliki nilai heritabilitas arti luas yang tinggi. Tinggi tanaman, diameter batang, bobot malai, dan bobot biji malai-1 memiliki nilai heritabilitas arti luas yang sedang. Jumlah daun dan diameter malai memiliki nilai heritabilitas arti luas yang rendah. Semua karakter berkorelasi positif dengan bobot biji malai-1. Diferensial seleksi tertinggi pada karakter tinggi tanaman dan kemajuan genetik tertinggi pada karakter bobot malai.
Keyword: evaluasi, generasi awal, heritabilitas, seleksi silsilah, sorgum

Judul: Evaluasi Karakter Agronomi Galur-galur Generasi Awal Sorgum (Sorghum bicolor (L.) Moench) Hasil Persilangan B-69 x Numbu
Abstrak: The objectives of this experiment were to evaluate performance and variability of agronomic characters of 62 F3, 31 BC1P1F2 and 31 BC1P2F2 of early generation lines of sorghum. This research was carried at Leuwikopo Experimental Farm, Bogor Agricultural University, Dramaga, Bogor from February to June 2013. The experiment was arranged in a randomized complete block design augmented with one factor genotype and 12 replications. The agronomic data was analyzed by comparing means of each line to the parental lines B-69 and Numbu. The results showed that the early generation lines showed significant difference with the parental lines, B-69 and Numbu for agronomic characters and yield components. The early generation lines from BC1P2F2 have higher mean value for stem diameter, crop height and biomass weight, compared to B-69 and Numbu, while the BC1P1F2 lines have lower crop height compared to B-69 and Numbu. The panicle weight and seed weight per plant have high heritability value, which allow for further selection.
Keyword: sorghum, early generation, heritability

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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