Judul: Deteksi dan ldentifikasi Nematoda Puru Akar pada Tanaman Krisan Berdasarkan Karakter Morfologi dan Molekuler
Abstrak: Chrysanthemum (Dendranthema grandiflorum Tzvelev) is a horticultural commodity that has significant economic value for Indonesia. One of the constraints in the production of chrysanthemum is infection of root knot nematodes (Meloidogyne spp.). The objective of this research was to identify species of Meloidogyne associated with chrysanthemum in West Java based on morphological and molecular characters. Morphological identification method is based on the shape and size of eggs, second stage juveniles, males and females perineal pattern of nematodes. Molecular identification was done through polymerase chain reaction (PCR) using primer pairs specific to M. incognita, M. javanica and M. arenaria. The result showed identification morphologically was found three species of Meloidogyne namely M. javanica, M. incognita and M. arenaria based on the molecular characterization, M. javanica is the only one of species that associated with chrysanthemum in West Java.
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Judul: Deteksi dan Identifikasi Nematoda pada Tanaman Krisan di PT Natalia Nursery, Kecamatan Tenjolaya, Kabupaten Bogor
Abstrak: Produksi tanaman krisan di Indonesia fluktuatif, namun cenderung meningkat selama periode 2012-2016. Kendala peningkatan produksi krisan salah satunya adalah penyakit yang disebabkan nematoda tanaman. Namun, penelitian tentang nematoda pada tanaman krisan masih sedikit. Penelitian ini bertujuan mendeteksi dan mengidentifikasi nematoda pada tanaman krisan. Pengambilan sampel tanaman krisan dilakukan dengan metode diagnostik berdasarkan gejala penyakit antara lain kerdil, daun menguning, dan distribusi tanaman sakit mengelompok. Ekstraksi nematoda dari sampel tanaman krisan dilakukan dengan metode penggabutan. Nematoda dibuat preparat semi-permanen dan diidentifikasi secara morfologi. Nematoda parasit tanaman pada tanaman krisan yaitu Rotylenchus, Pratylenchus dan Meloidogyne. Nematoda non-parasit pada tanaman krisan adalah Acrobeles, Prodorylaimus dan Dorylaimus.
Keyword: krisan, morfologi, nematoda, non-parasit, parasit

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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