Judul: Identifikasi Berbagai Aksesi Sagu (Metroxylon spp.) di Taman Nasional Siberut, Kepulauan Mentawai, Sumatera Barat
Abstrak: Tumbuhan sagu (Metroxylon spp.) merupakan salah satu tumbuhan penghasil karbohidrat yang potensial untuk dikembangkan dan memiliki kandungan karbohidrat terbesar dibanding tumbuhan penghasil karbohidrat lain. Keragaman jenis tumbuhan sagu di Indonesia masih banyak yang belum diketahui. Penelitian ini bertujuan mempelajari keragaman tumbuhan sagu berdasarkan karakter morfologi, karakter produksi dan karakter genetik yang dilakukan secara langsung melalui pengukuran (kuantitatif) dan pengamatan visual (kualitatif) di Taman Nasional Siberut, Kepulauan Mentawai, Sumatera Barat. Karakter genetik diamati menggunakan metode Random Amplified Polymorphic DNA (RAPD). Terdapat enam aksesi sagu yang diamati di dua Kecamatan Siberut Barat dan Siberut Utara, yaitu aksesi Saikoat, Limu, Betaet, Ukra, Sirilanggai dan Sibeotcun yang keseluruhan aksesi tersebut termasuk jenis sagu yang tidak berduri. Berdasarkan karakter morfologi, terdapat perbedaan dari keenam aksesi, seperti habitus dan habitat tumbuhan, bentuk tajuk, bentuk dan ukuran batang, jumlah daun, ukuran daun dan anak daun, warna kulit batang, warna empulur, warna pati, serta warna kuncup daun muda anakan. Rata-rata produksi pati kering berbagai aksesi sagu sebesar 312,68 kg batang-1. Aksesi Ukra merupakan aksesi yang memiliki produksi pati kering tertinggi sebesar 544,37 kg batang-1. Produktivitas sagu di Taman Nasional Siberut berdasarkan perhitungan jumlah pohon sagu siap panen per hektar didapatkan produktivitas sagu sebesar 15,79 ton hektar-1 tahun-1. Berdasarkan analisis karakter genetik (RAPD), terdapat keragaman yang cukup dekat dari keenam aksesi sagu yang terdapat di Taman Nasional Siberut, dengan nilai koefisien kemiripan berkisar antara 61% hingga 77%. Aksesi Ukra memiliki nilai koefisien kemiripan paling jauh dengan aksesi yang lainnya yaitu sebesar 61%., Sago (Metroxylon spp.) is one of the potential carbohydrate-producing plants to be developed and has the largest carbohydrate content compared to other carbohydrate-producing plants. The diversity of sago plant species in Indonesia is still largely unknown. This study aims to study the diversity of sago plants based on morphological, production, and genetic characteristic which were carried out directly through measurements (quantitative) and visual observations (qualitative) in Siberut National Park, Mentawai Islands, West Sumatra. Genetic characters were observed using the Random Amplified Polymorphic DNA (RAPD) method. There were six accessions of sago observed in two sub-districts of West Siberut and North Siberut, namely accessions of Saikoat, Limu, Betaet, Ukra, Sirilanggai, and Sibeotcun all of which included the thornless type of sago. Based on morphological characters, there were differences between the six accessions, such as habitus and plant habitat, crown shape, stem shape and size, number of leaves, leaf size and leaflets, stem bark color, pith color, starch color, and color of young leaf buds. The average dry starch production of various accessions of sago was 312.68 kg stem-1. The Ukra accession was the accession with the highest dry starch production of 544.37 kg stem-1. Sago productivity in Siberut National Park based on the calculation of the number of ready-to-harvest sago trees per hectare obtained sago productivity of 15.79 tons hectare-1 year-1. Based on genetic character analysis (RAPD), there is a fairly close diversity of the six sago accessions found in Siberut National Park, with similarity coefficient values ranging from 61% to 77%. Ukra accession has the closest similarity coefficient with other accessions, which is 61%.
Keyword: character, diversity, genetics, morphology, production

Judul: Identification of Sago Palm (Metroxylon spp.) Accession in Mamuju sub-District, Mamuju District, West Sulawesi Province
Abstrak: Sagu (Metroxylon spp.) merupakan tumbuhan yang berasal dari Indonesia, sekitar 85% sagu dunia terletak di Indonesia. Sagu memiliki potensi yang tinggi, khususnya sebagai tumbuhan pencegah kelaparan. Penelitian ini bertujuan mengidentifikasi aksesi sagu berdasarkan karakter morfologi, produksi, dan genetik di Kecamatan Mamuju, serta kekerabatan sagu di Provinsi Sulawesi Barat menggunakan metode RAPD. Analisis tutupan lahan sagu menggunakan metode pengindraan jauh juga dilakukan untuk mengetahui potensi produksi Kabupaten Mamuju. Terdapat 3 jenis sagu yang terdiri atas 2 jenis tidak berduri, yaitu Kasimpo, dan Kapas, serta 1 jenis berduri yakni Ruwi. Aksesi Kapas menjadi aksesi dengan produksi pati kering tertinggi, dapat mencapai 717,90 kg batang-1. Produktivitas sagu di Kecamatan Mamuju 15,03 ton pati kering ha-1 tahun-1. Produksi pati kering memiliki korelasi terbesar dengan panjang batang (0,872), jumlah daun (0,703), dan diameter batang (0,575). Hubungan kekerabatan (RAPD) berbagai aksesi di Provinsi Sulawesi Barat tidak begitu jauh, dengan nilai Kf <80%. Berdasarkan hasil pengindraan jauh berupa interpretasi citra satelit Pléiades-1A/-B, diketahui luas sagu di kabupaten Mamuju yaitu 252,74 ha. Tutupan lahan sagu terluas terletak di Kecamatan Kalukku yakni 95,27 ha dan tersempit di Kecamatan Kalumpang yaitu 0,91 ha. Peta yang dihasilkan memiliki akurasi sebesar 81,58%., Sago (Metroxylon spp.) is an original plant from Indonesia, about 85% of the world’s sago grown in Indonesia. Sago has a high potential, especially as a prevent hunger plant. The research aims to identify sago accession based on morphology, production and genetic in Mamuju sub-District, and the sago relationship in West Sulawesi Province using RAPD method. Sago land cover analysis using remote sensing method was used to estimate spotential sago production in Mamuju District. There were 3 accession observed, i.e. 2 type non spiny, Kasimpo and Kapas, and 1 type spiny it is Ruwi. Kapas is the hights production dry starch accession, it is reaching 717,90 kg trunk-1. Sago productivity in Mamuju sub-District is 15,03 tons dry starch ha-1 year-1. Dry starch production had the hights correlation with trunk length (0,872), number of leaves (0,703), and trunk diameter (0,575). Relationship (RAPD) various accession sago in West Sulawesi Province was not too far, Kf value <80%. Based on remote sensing with satellite Pléiades-1A/-B imagery interpretation, the sago area in Mamuju District estimated 252,74 ha. The largest sago area is in Kalukku sub-District, which is 95.27 ha and the narrowest is in Kalumpang sub-District, which is 0.91 ha. The map has 81.58% of overall accuracy.
Keyword: genetic, morphology, production, remote sensing, sago types

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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