Judul: Variability of Agronomic and Amylose of Population F3 Sorghum Derived from a Cross Pulut 3 x Soraya 3
Abstrak: Penggunaan sorgum sebagai alternatif pangan di Indonesia belum cukup berkembang karena tekstur sorgum yang pera kurang disukai masyarakat. Perbaikan terhadap kualitas biji sorgum perlu dilakukan untuk memperoleh sorgum berbiji pulen dan diterima masyarakat. Penelitian ini bertujuan mendapatkan informasi keragaman genetik pada populasi F3 sorgum hasil persilangan Pulut 3 x Soraya 3 serta seleksi cepat genotipe sorgum dengan kadar amilosa rendah. Penelitian ini dilaksanakan pada Juli 2022 hingga Desember 2022 di Kebun BBPSI Biogen, Cimanggu, Kecamatan Bogor Barat, Kota Bogor. Hasil penelitian menunjukkan rata-rata karakter kuantitatif yang beraneka ragam. Jumlah gen yang terlibat terbagi menjadi dua macam yaitu banyak dan sedikit gen. Aksi gen yang muncul yaitu epistasis. Hasil pewarnaan pada endosperma biji menunjukkan sebagian besar sorgum populasi F3 bertipe waxy., The use of sorghum as an alternative food in Indonesia has not been sufficiently developed because of the texture of sorghum is not liked by the public. Improvements to the quality of sorghum grains need to be carried out to obtain fluffier grained sorghum and be accepted by the public. This study aimed to obtain information on genetic variation in F3 sorghum populations from Pulut 3 x Soraya 3 and to select sorghum genotypes with low amylose content. This research was conducted from July 2022 to December 2022 at the BBPSI Biogen, Cimanggu, Bogor City. The results showed that the mean value of quantitative characters varied. The number of genes involved is divided into two kinds, namely many and few genes. Gene actions that appear are epistasis. The results of seed staining on grain’s endosperm showed that the majority of F3 sorghum was the waxy type
Keyword: epistasis, gene action, selection, staining

Judul: Diversity of Agronomical Characters and  Grain Type of Sorghum F2 Population Pulut 3 x Soraya 3
Abstrak: Pemanfaatan sorgum belum banyak dikembangkan di Indonesia karena kurang diminati oleh masyarakat. karena memiliki tekstur yang keras. Selain itu, terbatasnya varietas berdaya hasil tinggi menyebabkan produktivitas sorgum yang rendah. Penelitian ini bertujuan mendapatkan informasi keragaman karakter agronomi dan tipe biji sorgum, serta mendapatkan genotipe berdaya hasil tinggi dengan tipe biji waxy dari hasil persilangan Pulut 3 x Soraya 3 populasi F2. Penelitian ini dilaksanakan di Kebun Percobaan Muara, IP2TP Muara, Bogor pada bulan Agustus 2023 – Januari 2024. Hasil penelitian menunjukkan terdapat keragaman pada semua karakter agronomi yang diamati. Sebagian karakter yang diamati dikendalikan oleh aksi gen epistasis atau aditif tanpa epistasis dengan jumlah gen yang mengendalikan sedikit dan banyak. Terdapat keragaman karakter tipe biji sorgum yaitu tipe biji waxy dan non-waxy. Diferensial seleksi pada 30 genotipe waxy berdasarkan karakter diameter malai meningkatkan 31,3% bobot biji per malai., Utilization of sorghum has not been extensively developed in Indonesia due to its lack of public interest, primarily because of its hard texture. Additionally, the limited availability of high-yielding varieties has resulted in low sorghum productivity. This study aims to obtain information on the agronomic character diversity and grain type of sorghum, as well as to obtain high-yielding genotypes with waxy grain types from the crossbreeding of Pulut 3 x Soraya 3 F2 populations. The study was conducted at the Muara Experimental Garden, IP2TP Muara, Bogor, from August 2023 to January 2024. The research results showed that there is diversity in all observed agronomic characters. Most of observed characters are controlled by epistatic or additive actions without epistasis, with a small and large number of genes controlling them. There is diversity in sorghum grain types, including waxy and non-waxy types. Differential selection on 30 waxy genotypes based on inflorescence diameter increased the weight of grain per inflorescence by 31.3%.
Keyword: epistasis, tipe biji sorgum, aditif, diferensial seleksi

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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