Judul: Variability of Agronomic Characters and Amylose Content of Sorghum (Sorghum bicolor (L.) Moench) F2 Population Derived from a Cross Pulut 3 × Soraya 3
Abstrak: Pemuliaan sorgum dilakukan untuk memperoleh varietas unggul sorgum yang sesuai dengan petani dan konsumen. Faktor penting dalam keberhasilan merakit varietas unggul yaitu keragaman genetik yang tinggi. Penelitian ini bertujuan memperoleh informasi keragaman karakter agronomi serta kandungan amilosa sorgum populasi F2. Penelitian dilaksanakan pada bulan Februari-Juni 2022 di Cikarawang. Bahan genetik yang digunakan adalah sorgum populasi F2 Pulut 3 × Soraya 3, tetua, dan 9 genotipe pembanding. Pengamatan kandungan amilosa menggunakan pewarnaan iodin. Hasil penelitian menunjukkan, terdapat karakter-karakter agronomi yang memiliki nilai heritabilitas arti luas yang tinggi dengan nilai koefisien keragaman genetik (KKG) luas. Karakter agronomi dikendalikan oleh banyak gen dan sedikit gen dengan tipe aksi gen aditif, aditif dengan epistasis komplementer, dan aditif dengan epistasis aditif. Kandungan amilosa dikendalikan dua pasang gen dengan tipe aksi gen epistasis dominan ganda., Sorghum breeding is carried out to obtain superior varieties of sorghum that are suitable for farmers and consumers. An important factor in the success of assembling superior varieties is high genetic variability. This study aimed to obtain information on the variability of agronomic characters and amylose content in the F2 population. The research was conducted in February-June 2022 in Cikarawang. The genetic material used was sorghum population F2 Pulut 3 × Soraya 3, parents, and 9 comparison genotypes. Observation of amylose content using iodine staining. The results showed that there were agronomic characters that had a high broad heritability value with a high coefficient of genetic variability (KKG). Agronomic characters were controlled by many genes and few genes with additive gene action type, additive with complementary epistasis, and additive with additive epistasis. The amylose content was controlled by two pairs of genes with a double dominant epistasis gene action type.
Keyword: breeding, epistasis, gene action, heritability, iodine staining

Judul: Variability of Agronomic Characters and Waxy Types in the F2 Population of Sorghum (Sorghum bicolor (L.)  from Cross Pulut 3 × PI-150-20-A.
Abstrak: Sorgum berdasarkan kadar amilosanya, dapat dikelompokan menjadi tipe waxy dan non-waxy. Pemanfaatan sorgum tipe waxy belum banyak dilakukan, karena varietas sorgum berdaya hasil tinggi dan tipe waxy masih terbatas. Penelitian ini bertujuan untuk memperoleh informasi keragaman genetik, pendugaan aksi gen, dan pendugaan kandungan amilosa pada populasi F2. Penelitian dilaksanakan pada bulan Februari 2022 sampai Juli 2022 di Kebun Percobaan Cikarawang IPB. Populasi F2 yang digunakan yaitu hasil persilangan Pulut 3 × PI-150-20-A dan 11 genotipe pembanding. Rancangan yang digunakan yaitu rancangan kelompok lengkap teracak dengan satu faktor, yaitu genotipe dengan tiga ulangan. Berdasarkan hasil analisis ragam, terdapat keragaman pada semua karakter agronomi yang diamati. Karakter kuantitatif pada populasi F2 dikendalikan oleh sedikit dan banyak gen, dengan tipe aksi gen hanya aditif, epistasis duplikat dan epistasis komplementer. Karakter kualitatif yang diamati dikedalikan oleh dua pasang gen, dengan tipe aksi gen duplikat dominan epistasis atau isoepistasis., Sorghum based on its amylose content can be grouped into waxy and non-waxy types. The use of waxy sorghum has not been widely used, because high-yielding sorghum varieties and waxy types are still limited. This research was aimed to obtain information on genetic variance, estimate gene action, and estimate amylose content in the F2 population. The research was canducted from February to Juli 2022 at the Cikarawang Experiment field, IPB University. The F2 population used derived from Pulut 3 × PI-150-20-A and 11 chek genotypes. The design used was a complete randomized group design with one factor, namely the genotype with three replications. Based on the results of the analysis of variance, there is variabilty in all the observed agronomic characters. Quantitative characters in the F2 population is affected by many genes and gene slightly, type of gen action is simply additive, duplicate epistasis, and complementary epistasis. The observed qualitative characters were controlled by two pairs of genes, and type of gen action is isoepistasis.
Keyword: epistasis, gene action, heritability, iodine staining, selection

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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