Judul: Evaluasi Keragaman Genetik Kapulasan (Nephelium Ramboutan-Ake (Labill.) Leenh) Di Bogor, Jawa Barat Berdasarkan Marka Mikrosatelit
Abstrak: Kapulasan (Nephelium ramboutan-ake (Labill.) Leenh) merupakan tanaman yang mirip dengan rambutan rapiah (Nephelium lappaceum) dengan buah berbentuk bundar telur, cita rasa manis dan sedikit asam tetapi memiliki kulit buah yang tebal. Keanekaragaman kapulasan di pulau Jawa khususnya di Bogor belum diketahui sehingga perlu dilakukan evaluasi guna pengembangan jenis ini di masa depan. Tujuan penelitian ini adalah menganalisis keragaman genetik kapulasan di Bogor dengan marka mikrosatelit. Sejumlah 63 individu dari 10 populasi kapulasan diisolasi menggunakan metode CTAB lalu diamplifikasi menggunakan primer LMLY6 (GA)9(CA)2(GA)4 dan LMLY12 (CT)11. Hasil amplifikasi DNA divisualisasi dan disusun dalam matriks data biner lalu dianalisis menggunakan software GenAlex. Hasil analisis menggunakan GenAlex menunjukkan tingkat variasi genetik tertinggi ditemukan di Kecamatan Bogor Utara (He=0.313). Variasi genetik dalam populasi (61%) lebih tinggi dibandingkan dengan antar populasi (39%). Dendrogram kapulasan dikonstruksikan dengan metode Unweighted Pair Group Method with Arithmatic Mean (UPGMA) pada software NTSYS-pc ver 2.1. Nilai kesamaan seluruh sampel sebesar 52-100% dengan seluruh sampel tersebar dalam kelompok yang tidak mengikuti asal populasinya, namun pengelompokan kapulasan ditentukan oleh asal-usul individu kapulasan dalam populasi.
Keyword: Bogor, keragaman genetik, Nephelium ramboutan-ake, mikrosatelit

Judul: Keragaman Genetik Kerabat Rambutan Liar (Nephelium spp.) di Kabupaten Sanggau, Kalimantan Barat berdasarkan Marka SSR dan ISSR.
Abstrak: Wild rambutans (Nephelium spp.) are members of Sapindaceae that produce edible fruit. This study aimed to determine the genetic diversity of wild rambutan from district Sanggau, West Kalimantan based on SSR and ISSR markers. Plant materials were colected from five subdistricts, Bonti, Jangkang, Parindu, Mukok and Kapuas, district Sanggau, West Kalimantan. There were four species and five varieties of wild rambutans in West Kalimantan, namely N. cuspidatum, N. lappaceum, N. rubescens, and N. uncinatum. The genetic diversity of wild rambutans in West Kalimantan is high. The highest genetic diversity based on SSR markers was found in Jangkang (He=0,27) and the highest genetic diversity based on ISSR was found in Bonti (He=0,18). Cluster analysis using Simple Matching (SM) index and UPGMA method based on SSR and ISSR showed that there were high similarity among species of wild rambutans in district Sanggau, West Kalimantan with similarity index ranged 0,5 – 1,0.
Keyword: Bogor Agricultural University (IPB), wild rambutan, SSR, Nephelium, ISSR, Genetic diversity

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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