Judul: Induksi Keragaman Somaklonal Beberapa Kultivar Krisan (Dendrathema grandiflora Tzvelev.) Melalui Iradiasi Sinar Gamma Secara In Vitro Untuk Memperoleh Klon Krisan Baru
Abstrak: Penelitian ini bertujuan untuk mempelajari pengaruh dari iradiasi sinar gamma terhadap variasi genetik tanaman krisan dalam kultur in vitro, untuk mengetahui dosis sinar gamma yang optimum untuk menginduksi variasi somaklonal pada empat varietas krisan, untuk membandingkan ketahanan tanaman terhadap sinar gamma di antara empat kultivar krisan, dan untuk mengetahui interaksi antara kedua faktor, yaitu faktor kultivar dan dosis sinar gamma. Penelitian ini dilaksanakan dari bulan April-Agustus 2009 di Laboratorium Bioteknologi Departemen Agronomi dan Hortikultura IPB. Percobaan menggunakan rancangan faktorial acak kelompok dengan dua faktor. Faktor pertama yaitu kultivar krisan yang terdiri atas Puspita Nusantara, Puspita Asri, Cut Nyak Dien, dan Dewi Ratih. Faktor kedua adalah dosis sinar gamma, yaitu 0, 0.5, 1, 1.5, dan 2 krad yang diulang sebanyak 5 kali. Pertumbuhan terbaik terdapat pada krisan kultivar Puspita Nusantara pada dosis 0 krad. Dosis 0.5 krad atau lebih dapat menginduksi keragaman somaklonal kultivar Puspita Nusantara, Puspita Asri, Cut Nyak Dien, dan Dewi Ratih. Dosis sinar gamma secara nyata menghambat pertumbuhan jumlah daun, namun tidak berpengaruh nyata terhadap jumlah tunas dan tinggi tanaman. Nilai LD50 masing-masing kultivar melebihi dosis yang diberikan dalam percobaan, yaitu kultivar Puspita Nusantara 5.93 krad, Puspita Asri 6.61 krad, Cut Nyak Dien 6.81 krad, dan Dewi Ratih 12.77 krad.
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Judul: Induksi Keragaman Dua Varietas Krisan (Dendranthema grandiflora Tzvelev) Dengan Iradiasi Sinar Gamma Secara In Vitro
Abstrak: The research aims were to study the effect of gamma irradiation doses on Chrysanthemum (Dendranthema grandiflora Tzvelev) and increasing the genetic diversit. The research were conducted at IPB Tissue Culture Laboratory, BATAN Laboratory, and IPB Micro Tehnique Laboratory, during February–November 2010. This research used completely randomized design with two factors. The first factor is varieties of Chrysanthemum, including Dewi Ratih and Puspita Nusantara. The second factor is five doses of gamma irradiation (0, 20, 40, 60, 80 Gy). The result showed that the interaction between varieties with doses of gamma irradiation affected growth of plants and the number of chloroplast in guard cell. The number and size (length and width) of stomata were influenced by a varieties and and irradiation dose as a single factor. Increasing doses of gamma irradiation could increase the length and width of stomata. LD50 of krisan planlets were obtained 22.22 Gy for Dewi Ratih and 22.85 Gy for Puspita Nusantara. The gamma radiation dose 20 Gy produced 13 potential mutant on Dewi Ratih and Puspita Nusantara varieties. Putative mutants characteristic showed small leaves and no serrated, reddish stems, stunted, rosette, and variegata leaves.
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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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