Judul: Effectiveness of Several Commercial Product  as the Source of Plant Growth Regulators in the Growth of Phalaenopsis amabilis  Protocorm
Abstrak: Phalaenopsis amabilis merupakan salah satu jenis anggrek yang popular dengan keindahan bunganya. Perbanyakan anggrek P. amabilis melalui protocorm dapat menghasilkan tanaman dalam jumlah besar dan genetik yang stabil Pertumbuhan normal pada protocorm dibutuhkan untuk mendapatkan planlet dengan kualitas yang baik sebelum aklimatisasi. Penelitian bertujuan mempelajari keefektifan beberapa sumber ZPT alternatif dalam pertumbuhan protocorm P. amabilis. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan faktor tunggal. Bahan tanam yang digunakan adalah protocorm P. amabilis yang dihasilkan benih yang berasal dari bunga hasil penyerbukan sendiri (selfing). Benih ditabur pada media 1⁄2 MS + air kelapa 15% + gula 30 g + agar 7 g per liter pada tanggal 23 September 2020. Protocorm yang berumur 6 bulan setelah perkecambahan dipindahkan ke 10 perlakuan media perbanyakan yang mengandung zat pengatur tumbuh (zpt) alternatif yaitu 1⁄2 MS (K0), (1⁄2 MS + 0,25 ml L-1 Atonik (A1), 1⁄2 MS + 0,5 ml L-1 Atonik (A2), 1⁄2 MS + 1 ml L-1 Atonik (A3), 1⁄2 MS + 0,025 ml L-1 Agrogibb (G1), 1⁄2 MS + 0,05 ml L-1 Agrogibb (G2), 1⁄2 MS + 0,075 ml L-1 Agrogibb (G3), 1⁄2 MS + 0,5 ml L-1 NovelGro (N1), 1⁄2 MS + 1 ml L-1 NovelGro (N2), 1⁄2 MS + 2 ml L-1 NovelGro (N3). Protocorm dibedakan menjadi tiga ukuran yaitu kecil, sedang dan besar. Setiap perlakuan zpt alternatif memiliki tiga ulangan (tiga kelompok ukuran) dengan lima protocorm pada masing-masing botol, masing-masing tiga botol per perlakuan. Protocorm diamati untuk mendapatkan persentase eksplan hidup, jumlah tunas, waktu terbentuk tunas, jumlah daun, jumlah akar, panjang daun, lebar daun dan panjang akar. Protocorm sedang ditandai dengan ukurannya yang sedang dan bentuk bulat tanpa tonjolan. Perlakuan terbaik pertumbuhan protocorm adalah 1⁄2 MS (K0). Media ini menunjukkan tidak adanya pertumbuhan abnormal protocorm. Perlakuan 1⁄2 MS + 0,075 ml L-1 Agrogibb (G3) mampu mendukung pemanjangan protocorm, tunas dan daun. Protocorm besar menghasilkan jumlah tunas paling banyak pada 4 dan 5 MST. Protocorm besar juga menghasilkan jumlah daun dan jumlah akar paling banyak pada 6 MST. Kata kunci: Agrogibb, Atonik, NovelGro, Phalaenopsis amabilis, Protocorm., Phalaenopsis amabilis is one of the most popular orchid’s species caused by its beautiful flower. Multiplication P. amabilis by using protocorm can produce plants with high quantity and stable genetics. The normal growth of the protocorm is needed to get good quality plantlets before acclimatization. The research aimed to study the effectiveness of several alternative plant growth regulators on the growth of P. amabilis protocorm. This research was arranged in a Randomized Complete Block Design with alternative growth regulators as the single factor. The plant material used was protocorm of P. amabilis resulting from seed from flower self-pollination. The seeds were germinated on 1⁄2 MS medium + 15% of coconut water + 30 g of sucrose + 7 g of agar per liter on 23 September 2020. Protocorm at 6 months after germination were transferred to 10 treatments of multiplication medium containing alternative source of plant growth regulators namely 1⁄2 MS (K0), (1⁄2 MS + 0.25 ml L-1 Atonik (A1), 1⁄2 MS + 0.5 ml L-1 Atonik (A2), 1⁄2 MS + 1 ml L-1
Keyword: Agrogibb, Atonik, NovelGro, Phalaenopsis amabilis, Protocorm

Judul: Pertumbuhan Protocorm Like Bodies (Plb) Dua Populasi Hasil Persilangan Anggrek Phalaenopsis pada Beberapa Komposisi Media
Abstrak: In vitro propagation of orchids had shortened the time required to produce plants in large quantities. The objective of this research was to determine the effect of medium composition on the growth of protocorm like bodies (Plb) of two populations of Phalaenopsis hybrid. Research laid out in completely randomized design with two factors, namely the Phalaenopsis hybrid populations and medium composition. The first hybrid of population was generated from a crossing between the white standard and the pink standard of Phalaenopsis hybrid accession and the second hybrid was the reciprocal of the first crossing. Seeds were germinated on MS 1/2 to produce Plb, then the Plb subsequently cultured in four media composition, i.e MS 1/2 , MS 1/2 + coconut water 150 ml l-1, complex fertilizer Hyponex (2 g l-1), and Hyponex (2 g l-1) + coconut water 150 ml l-1. The results showed that the increase of Plb was significantly influenced by population, medium composition, and the interaction between the two factors. Population 1 showed better growth (average 5.4 Plb per 16 weeks) compared with the population 2 (average 2.2 Plb per 16 weeks). The best medium for the growth of Plb into plantlets in both populations is Hyponex (2 g l-1) or Hyponex (2 g l-1) + coconut water 150 ml l-1.
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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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