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 and Amylose  Content of F2 Population of Sorghum Derived from a Cross Pulut 3 × Kawali
Abstrak: Sorgum adalah tanaman pangan terpenting kelima di dunia dan dapat dimanfaatkan sebagai pakan dan bioenergi. Agar sorgum dapat diterima sebagai sorgum pangan, khususnya sebagai beras, maka perlu dilakukan perbaikan kadar amilosa melalui kegiatan pemuliaan tanaman, yaitu mengembangkan varietas sorgum dengan tipe heterowaxy. Tujuan penelitian ini untuk memperoleh informasi tentang keragaman genetik pada karakter agronomi dan kandungan amilosa pada generasi F2 sorgum Pulut 3 × Kawali. Penelitian dilaksanakan dari bulan Februari sampai Juni 2022 di Kebun Percobaan Cikarawang, Dramaga Bogor. Bahan genetik yang digunakan populasi F2 sorgum Pulut 3 × Kawali, 2 tetua dan 9 pembanding. Hasil penelitian menunjukkan nilai tengah karakter populasi F2 sorgum Pulut 3 × Kawali berbeda nyata terhadap kedua tetua. Hasil uji lanjut DMRT menunjukkan adanya perbedaan karakter antara genotipe pembanding dan tetua. Analisis kurtosis menunjukkan karakter dikendalikan oleh sedikit gen dan banyak gen serta analisis skewness menunjukkan karakter dikendalikan oleh tipe aksi gen dominan, aditif, epistasis komplementer dan espistasis duplikat. Analisis heritabilitas arti luas bervariasi dari rendah, sedang, tinggi. Hasil dari karakter kualitatif keberadaan amilosa pada pewarnaan biji menunjukkan bahwa hasil dikendalikan oleh satu pasang gen dominan., Sorghum is the fifth most important food crop in the world and it can be used as food, feed and bioenergy. To be accepted as food, especially as rice, it is necessary to improve the amylose content through plant breeding activities to develop sorghum varieties with heterowaxy types. The purpose of this study was to obtain information on genetic variation in agronomic characters and amylose content in F2 shorgum generation. The research was conducted from February to June 2022 at Cikarawang experimental field, Dramaga Bogor. The genetic materiasl used were F2 shorgum population Pulut 3 × Kawali, 2 parents, and 9 comparisons. The results showed that the mean value of the population character F2 shorgum Pulut 3 × Kawali was significantly different from the two parents. The results of the DMRT test showed differences between the comparison and parental genotypes. Kurtosis analysis indicates that the observed characters controlled by few and many genes. Meanwhile, skewness analysis showed that the characters were controlled by dominance, additive, and epistasis genes action. Heritability analysis was vary low to high. The presence amylose based on seed staining showed that character controlled by one pair of dominance genes.
Keyword: breeding, heterowaxy, F2 population, sorghum, variability

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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