Judul: Variasi Genetik dan Teknik Perbanyakan Vegetatif Cemara Sumatra (Taxus sumatrana)
Abstrak: Genetic diversity and vegetatif propagation technique for Sumatran yew (Taxus sumatrana) are little known and could be useful for the management of this long-lived species either for conservation, habitat restoration or production of paclitaxel (Taxol® ), a promising anti-cancer agent. The objective of this research were: 1) To estimate genetic variation of Sumatran yew from three reproductive population (mother tree, planted tree in Cibodas Botanical Garden and natural seedling) using RAPD marker that is important in formulating appropriate conservation strategies for the species; and 2) To find out suitable rooting medium in propagating Sumatran yew vegetatively. In this study, the genetic diversity was estimated based on Random Amplified Polymorphic DNA (RAPD). Of the 28 universal primers screened, six produced polymorphic and clear RAPD bands. The result also showed that there was a relatively high genetic diversity within population with the percentage of polymorphic band (PPB) ranging from 45,8% – 83,33% with an average 69,43% and Nei’s genetic diversity index (He) of 0,2346, and moderate genetic differentiation among population (GST = 0,2892 ). The high genetic diversity found on population of Sumatran yew may result from their life history characteristic as an outcrossing, widespread distribution, wind-pollinated, animal digested seed and long-lived woody species. Results from shoot cutting experiment using three different rooting media showed that rooting ability was significantly affected by the medium. Among the three media tested, combination of cocodust and rice husk at the ratio 2:1 (v/v) gave the best result in rooting ability (66,7%).
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Judul: Teknik Perbanyakan dan Kekerabatan Genetik Pasak Bumi (Eurycoma longifolia Jack)
Abstrak: Pasak bumi (Eurycoma longifolia Jack) is a shrubs growing wildly in the forests of Southeast Asia and widely used throughout the region because of its medicinal properties. Uncontrolled harvesting of wild-grown trees has led to rapid decrease of natural populations, as well as causing a potential decrease in genetic diversity. The objectives of this research were 1). To get information about propagation technique of pasak bumi by seed and stem cutting and its suitable growing medium and 2). To estimate genetic relatedness of pasak bumi propagated by seed collected from Jambi using RAPD marker. Propagation by seed produced low germination percentage (14-34%) at different media. Seedling planted in pure carbonized rice husk medium produced the best growth variabel on vigority, primary root number, secondary root number, primary root length and secondary root length. Result from stem cutting showed that medium significantly improved secondary root length, while rooting percentage, primary root length and the number of root significantly was affected by Rootone F treatment. Genetic relatedness by RAPD marker showed that pasak bumi propagated by seed has high value of genetic diversity within population (He = 0,3076) and 78,57% all the loci tested were polimorphic, clustering analysis showed that the plant can be grouped into two group.
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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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