Judul: Isolasi Bakteri Endofit dari Tanaman Kehutanan dan Potensinya untuk Pengendalian Meloidogyne spp. pada Tanaman Tomat
Abstrak: Meloidogyne spp. is one of the main constraints of tomato production in Indonesia. Endophytic bacteria as a biocontrol agents is an alternative for controlling nematodes. The objective of this study was to isolate endophytic bacteria from forest plants and to evaluate its potential for controlling Meloidogyne spp. on tomato (Lycopersicon esculentum Mill.). Endophytic bacteria were isolated from mahoni (Swietenia mahogany Jacq), trambesi (Albizia saman (Jacq.) Merr.), gaharu (Aquilaria malacensis), and meranti (Shorea sp.) with surface sterilization method using 70% alcohol, 4% NaOCl and steril water. The bacterial strain were cultured on tryptic soy agar (TSA) for two days. In vivo testing to determine the effect of bacteria for suppressing of nematode galls was conducted in the greenhouse with seed treatment. The result showed there are thirty three isolates of endophytic bacteria were isolated from the root of forest plant. twenty two isolates are negative reaction and eleven isolates are positif reaction after hypersensitive test using tobacco plant. Two isolates of endophytic bacteria MSJ1H and TSS1D were able to reduce gall number. Based on high plant indicator, soaking seed treatment with endophytic bacteria were able to increase the high of tomato plants.
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Judul: Seleksi Bakteri Endofit dari Tanaman Jabon, Sengon dan Tanjung untuk Pengendalian Meloidogyne sp. pada Tanaman Tomat.
Abstrak: Nematoda puru akar Meloidogyne sp. merupakan nematoda parasit tumbuhan yang menyerang akar dan menjadi masalah pada tanaman tomat. Tujuan dari penelitian ini adalah untuk menyeleksi bakteri endofit dari tiga spesies tanaman hutan, Jabon (Anthocephalus cadamba Miq.), Sengon (Albizia chinensis (Osbeck) Merr.) dan Tanjung (Mimusops elengi L.) serta mengevaluasi potensinya untuk pengendalian Meloidogyne sp. pada tanaman tomat. Bakteri endofit diisolasi dengan metode sterilisasi permukaan dengan menggunakan TSA sebagai media tumbuh. Sebanyak 11 isolat bakteri endofit berhasil diperoleh dari tiga akar tanaman tersebut. Hasil uji hipersensitif pada daun tembakau menunjukkan semua isolat bakteri endofit tidak berpotensi sebagai bakteri patogen. Beberapa isolat memiliki potensi untuk menekan dan mengurangi timbulnya puru akar pada tanaman tomat hingga lebih dari 80%.
Keyword: hipersensitif, isolat, nematoda, parasit tumbuhan, puru akar

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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