Judul: Application Types and Concentrations of Media and Concentrations of BAP on Secondary Protocorm and Planlet Induction of Dendrobium tobaense var. giganteum
Abstrak: Anggrek genus Dendrobium merupakan jenis anggrek yang memiliki nilai ekonomi tinggi dan banyak diminati. Hal tersebut menyebabkan beberapa spesies mulai terancam keberadannya, salah satunya yaitu Dendrobium tobaense var. giganteum. Penelitian ini bertujuan mempelajari pengaruh jenis dan konsentrasi media serta BAP dalam menginduksi proliferasi protocorm sekunder dan planlet D. tobaense var. giganteum secara in vitro. Jenis media yang digunakan yaitu Knudson C, Schenk and Hildebrant, dan Vacin and Went dengan konsentrasi 1/2 dan 3/4 kali konsentrasi hara makro dan mikro. Zat pengatur tumbuh BAP (Benzyl Amino Purine) yang ditambahkan yaitu 0, 1, 2, dan 3 mg L-1. Eksplan yang digunakan adalah protocorm primer D. tobaense var. giganteum aksesi dari hutan Aceh Tengah. Hasil penelitian ini menunjukkan jenis media berpengaruh sangat nyata terhadap pembentukan protocorm sekunder dan tunas D. tobaense var. giganteum. Media yang optimal untuk proliferasi protocorm membentuk protocorm sekunder dan menghasilkan jumlah protocorm sekunder tertinggi yaitu media 1/2 SH sebanyak 1,68 protocorm sekunder. Interaksi jenis media dengan konsentrasi BAP berpengaruh nyata terhadap jumlah kalus. Sebanyak 1,13 kalus berhasil terbentuk pada media 1/2 VW + 2 mg L-1 . Pada pembentukan tunas diperoleh kombinasi media yang optimal yaitu media 1/2 SH + 2 mg L-1 BAP dengan rata- rata jumlah tunas 4,08 tunas per eksplan., Orchid genus Dendrobium is a type of orchid that has high economic value and is in great demand. This has caused several species to be threatened, one of which is Dendrobium tobaense var. giganteum. This study aimed to study the effect of the type and concentration of media and BAP in inducing proliferation of secondary protocorms and plantlets of D. tobaense var. giganteum in vitro. The types of media used were Knudson C, Schenk and Hildebrant, and Vacin and Went with concentrations of 1/2 and 3/4 times the concentration of macro and micronutrients. The growth regulators BAP (Benzyl Amino Purine) added were 0, 1, 2, and 3 mg L-1. The explants used were primary protocorm D. tobaense var. giganteum accession from the forests of Aceh Tengah. Result of this experiment is the type of media had a very significant effect on the formation of the secondary protocorm and shoots of D. tobaense var. giganteum. The optimal medium for protocorm proliferation formed a secondary protocorm and produced the highest number of secondary protocorms, namely 1/2 SH media as much as 1.68 secondary protocorms. The interaction of the type of media with the concentration of BAP significantly affected the number of callus. A total of 1.13 callus were successfully formed on 1/2 VW + 2 mg L-1 media. In the formation of shoots, the optimal combination of media was obtained, namely media 1/2 SH + 2 mg L-1 BAP with an average number of shoots of 4.08 shoots per explant.
Keyword: protocorm, Dendrobium tobaense var. giganteum, Benzyl Amino Purine, Knudson C, Schenk and Hildebrant, Vacin and Went

Judul: The Effects of 2,4-D, BAP, NAA, and Organic Compounds on Seed Germination and Protocorm Development of Dendrobium stratiotes Rchb. f.
Abstrak: Dendrobium stratiotes merupakan anggrek yang memiliki bunga yang indah sehingga bernilai ekonomi tinggi. Penelitian bertujuan mempelajari perkecambahan benih dan perkembangan protokorm anggrek pada komposisi media perkecambahan dan pembesaran in vitro yang berbeda. Penelitian terdiri atas dua percobaan. Percobaan 1 menguji penambahan bahan organik dan zat pengatur tumbuh (ZPT) dengan konsentrasi tertentu pada media untuk perkecambahan. Percobaan ini menggunakan rancangan acak lengkap (RAL) satu faktor yaitu bahan tambahan dalam media ½MS dengan 5 taraf yaitu 1,4 g l-1 pepton, 15% air kelapa, 1,4 g l-1 pepton+15% air kelapa, 2,0 ppm BAP+0,1 ppm 2,4-D, dan 2,0 ppm BAP+0,1 ppm 2,4-D+15% air kelapa. Percobaan 2 adalah penambahan ZPT pada media perkembangan protokorm dengan konsentrasi tertentu. Percobaan ini menggunakan RAL satu faktor yaitu tambahan ZPT dalam media ½MS+pepton dengan 5 taraf yaitu kontrol (tanpa penambahan ZPT), 0,5 ppm BAP, 1,0 ppm BAP, 0,5 ppm BAP+0,1 NAA, dan 1,0 ppm BAP+0,1 NAA. Hasil penelitian menunjukkan bahwa rerata perkecambahan tertinggi dihasilkan pada kombinasi pepton dan air kelapa. Kecepatan perkecambahan benih tercepat pada penambahan pepton. Rerata kemunculan akar rambut tertinggi pada kontrol. Rerata pembentukan mata tunas tertinggi ada pada penambahan 0,5 ppm BAP+0,1 ppm NAA. Rerata protokorm yang membentuk kalus tertinggi pada penambahan 1,0 ppm BAP+0,1 NAA., Dendrobium stratiotes is an orchid that has high economic value because of its beautiful flowers. This research aimed to study the seed germination and protocorm development of the orchid in different in vitro germination and development media compositions. The research consisted of two experiments. In the first experiment, organic additives and plant growth regulators (PGRs) are added to the media for germination with certain concentrations. The experimental design in this step used a single factor completely randomized design (CRD) which is additional additives in ½ MS media with 5 levels of additives i.e. 1,4 g l-1 peptone, 15% coconut water, 1,4 g l-1 peptone + 15% coconut water, 2,0 ppm BAP + 0,1 ppm 2,4-D, and 2,0 ppm BAP + 0,1 ppm 2,4-D + 15% coconut water. The second experiment is the addition of PGRs to the media for protocorm development with certain concentrations. The experimental design in this step is using a single factor CRD which is the addition of PGRs in ½ MS + peptone media with 5 levels of PGRs i.e. control (without PGRs addition), 0,5 ppm BAP, 1,0 ppm BAP, 0,5 ppm BAP + 0,1 ppm NAA, and 1,0 ppm BAP + 0,1 ppm NAA. The results showed that the highest germination rate was produced in the medium containing the combination of peptone and coconut water. The fastest seed germination was in the medium with the addition of peptone. The highest average emergence of absorbing hair root of protocorm is in the control treatment. The highest average shoot bud formation was in the addition of 0,5 ppm BAP + 0,1 ppm NAA. The highest average of protocorm that formed callus was in the addition of 1,0 ppm BAP + 0,1 ppm NAA.
Keyword: absorbing hair root, auxin, callus, cytokinin, shoot

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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