Judul: Penyimpanan dengan Pertumbuhan Minimal dan Regenerasi In Vitro Purwoceng (Pimpinella pruatjan Molk.)
Abstrak: Purwoceng merupakan tanaman obat asli Indonesia yang memiliki nilai ekonomi tinggi. Akarnya memiliki khasiat afrodisiak yaitu dapat meningkatkan gairah seksual dan meningkatkan ereksi, melancarkan air seni (diuretik) dan meningkatkan stamina tubuh (tonik). Saat ini populasi purwoceng di habitat alaminya sudah punah akibat eksploitasi secara besar-besaran sebagai bahan baku jamu tanpa adanya usaha penanaman kembali. Selain itu purwoceng sulit dibudidayakan di luar habitat alaminya karena memiliki persyaratan tumbuh yang spesifik. Oleh karena itu purwoceng dikategorikan sebagai tanaman langka yang sangat dilindungi. Untuk menghindari kepunahan purwoceng perlu dilakukan upaya konservasi sesegera mungkin. Konservasi in vitro tanaman purwoceng melalui pertumbuhan minimal menggunakan paklobutrazol 1 ppm pernah dilaporkan, namun hasilnya kurang memuaskan dimana kultur tidak dapat disimpan dalam waktu lebih dari empat bulan. Upaya untuk meningkatkan umur penyimpanan purwoceng dapat dilakukan dengan menggunakan secara bersama-sama dua faktor penghambat pertumbuhan yaitu regulator osmotik sorbitol dan retardan pertumbuhan paklobutrazol. Dalam penyimpanan, diharapkan kultur tidak hanya mampu disimpan lama namun harus memiliki daya regenerasi yang tetap tinggi. Tujuan penelitian ini untuk mendapatkan konsentrasi perlakuan terbaik dalam penyimpanan secara in vitro purwoceng dengan periode lebih lama (8 bulan), menguji daya regenerasi, stabilitas struktur morfologi dan anatomi daun regenerasi pasca penyimpanan. Formulasi terbaik diharapkan dapat diterapkan secara rutin sebagai protokol penyimpanan in vitro di bank gen untuk menghindari kepunahan spesies langka ini
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Judul: Penyimpanan in vitro dengan teknik pertumbuhan minimal dan regenerasi pasca penyimpanan kultur purwoceng (Pimpinella pruatjan Molk.)
Abstrak: Purwoceng is one of the rare medicinal plants of Indonesia which is categorized as endangered plant because of the exploitation without replanting and the damage of natural habitat. Roots extracts of this medicinal plant can be used as diuretics, tonics, and especially as aphrodisiacs. Preliminary research found that purwoceng can be good conserved in vitro with minimal growth technique on DKW medium with 30 grams of sucrose, 1% sorbitol without paklobutrazol (S1P0); and 3% sorbitol and 1 ppm paklobutrazol (S3P1) in the storage period of four months and eight months. However, their regeneration within three months in media DKW + BA 4 ppm + Thidiazuron (TDZ) 0,4 ppm + Glutamin 100 ppm that added with GA3 3 ppm decreased and they maintained their dwarf morphology in the regeneration stage. Effect of sorbitol and paklobutrazol treatment during storage was still brought. This research was conducted by planting of axillary buds purwoceng which was grown on the storage media within six months of storage period. The regeneration was carried out for two months on DKW medium with 30 grams of sucrose, combination of GA3 (0, 1, 3, 5 ppm) and BAP (0, 1, 2, 3 ppm). The good treatment in this storage phase was S1P0. Explants of S1P0 had tend to grow slowly and normally, produced good roots and good condition; whereas explants of S3P1 slow growth rate, dwarf and poor of root. The good combination at regeneration phase from explants of S1P0 was G1B1 (GA3 1 ppm and BAP 1 ppm) and G5B0. The treatment of G1B1 and G5B0 produced fertile and no dwarfts plants which have high growth rate, their culture vitality were normal, and they produce root.
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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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