Judul: Identification of Leaf Agronomic and Physiological Characters of Several Genotypes of Cassava (Manihot esculenta Crantz)
Abstrak: Daun ubi kayu menjadi salah satu sayur konsumsi harian sehingga peningkatan kualitas dan kuantitas daun ubi kayu perlu dilakukan melalui pemuliaan tanaman dengan peningkatan keragaman ubi kayu. Departemen AGH IPB memiliki beberapa genotipe mutan stabil hasil iradiasi sinar gamma yang berpotensi menjadi varietas baru penghasil daun. Tujuan penelitian ini untuk memilih genotipe unggul tanpa merusak daun melalui pembelajaran karakter agronomi dan fisiologi daun beberapa genotipe ubi kayu serta mempelajari korelasi antara kandungan klorofil dengan hasil klorofil meter SPAD (Soil Plant Analysis Development). Penelitian dilakukan dengan mengamati tinggi tanaman, lebar tanaman, indeks luas daun (ILD) daun ke-5, jumlah cabang dan tingkat hijau daun pada 35 genotipe yang berasal dari 6 tetua. Genotipe unggul yang diperoleh melalui pengolahan hasil pengamatan antara lain G2D12223 (tanaman asal Ratim), G3D2413 (tanaman asal UJ-5), G21533 dan G31515D (tanaman asal Gajah). Keempat genotipe tersebut diuji kandungan klorofil untuk melihat pengaruh genotipe pada klorofil dan korelasi antara tingkat hijau daun hasil SPAD dengan kandungan klorofil. Hasil uji anova dan uji lanjut menunjukkan genotipe memberikan pengaruh pada tingkat hijau daun, klorofil b, rasio klorofil a:b dan karoten. Genotipe yang unggul adalah G31515D untuk semua karakter kecuali rasio klorofil a:b dan G21533 untuk karakter rasio klorofil a:b. Hasil uji korelasi menunjukkan tingkat hijau daun berkorelasi nyata terhadap total klorofil, klorofil a, klorofil b, rasio klorofil a:b dan karoten sedangkan antosianin tidak berkorelasi dengan semua karakter uji lainnya. Kata kunci: cassava, dikotil, genotipe, karoten, klorofil, Cassava leaves are one of the vegetables for daily consumption so the quality and quantity of cassava leaves should be improved through plant breeding by increasing the diversity of cassava. The AGH Department of IPB has several stable mutant genotypes resulted from gamma-ray irradiation which have the potential to become new leaf-producing varieties. The purpose of this study was to select superior genotypes without damaging the leaves through studying the agronomic and physiological characters of several cassava genotypes and studying the correlation between chlorophyll content and the results of the chlorophyll meter SPAD (Soil Plant Analysis Development). The research is conducted by observing plant height, plant width, leaf area index (LAI) of the 5th leaf, number of branches, and leaf green level in 35 genotypes from 6 parents. The superior genotypes obtained through processing the observations included G2D12223 (plants from Ratim), G3D2413 (plants from UJ-5), G21533, and G31515D (plants from Gajah). The four genotypes were tested for chlorophyll content to see the effect of the genotype on chlorophyll and the correlation between the green level of the leaves from the SPAD results and the chlorophyll content. ANOVA test results and further tests showed that the genotype affected the level of leaf green, chlorophyll b, the ratio of chlorophyll a: b and carotene. The superior genotype was G31515D for all characters except chlorophyll a: b ratio and G21533 for chlorophyll a: b ratio characters. The results of the correlation test showed that the level of leaf green was significantly correlated with total chlorophyll, chlorophyll a, chlorophyll b, the ratio of chlorophyll a: b, and carotene, while anthocyanin is not correlated with all other test characters. Keywords: cassava, chlorophyll, carotene,
Keyword: cassava, chlorophyll, carotene, dicotyledoneae, genotype

Judul: Keragaan dan Keragaman Mutan Tanaman Ubi Kayu (Manihot esculenta Crantz.) Hasil Iradiasi Sinar Gamma Serta Pendugaan Heritabilitas
Abstrak: Cassava is a potential crop for food, industry (food and feed), and bioenergy if developed suit with their characteristics. This research intended to identify the second generation (M1V2) cassava mutants from gamma ray irradiation. The irradiated cassava varieties are Ratim, UJ-5, and Malang-4. The result show that mutant variability appears on mutants plant performance (plant height, plant branching, tubers weight, number of tubers and economic tubers, cortex thickness and tuber qualitative characters). Variability in each genotype also appears on the tuber performance in this generation. Broad sense heritability estimation on number of tubers, number of economic tubers and cortex thickness were classified as high score and can used as third generation mutant selection criteria. The shelf life of cassava tubers depends on postharvest physiology deterioration (PPD) and marked by changes in water content and tuber discoloration, PPD occurs in almost all mutant genotype samples stored up to 21 days.
Keyword: Bogor Agricultural University (IPB), storage root, mutant, characterization, M1V2 generation

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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