Judul: Deteksi Dan Identifikasi Pepper Vein Yellows Virus Penyebab Penyakit Kuning Pada Tanaman Mentimun Di Jawa Barat
Abstrak: Survei pada pertanaman mentimun di daerah Jawa Barat dilaporkan adanya gejala menguning dan vein banding. Gejala ini mirip dengan gejala penyakit klorosis pada cabai yang telah dilaporkan di Bali. Penyakit tersebut diketahui diinduksi oleh Pepper vein yellows virus (PeVYV; Polerovirus), yang diketahui memiliki inang yang terbatas pada tanaman cabai. Penelitian ini bertujuan untuk mendeteksi dan mengidentifikasi virus yang berasosiasi dengan penyakit kuning pada tanaman mentimun melalui reverse transcriptionpolymerase chain reaction (RT-PCR) dan analisis sikuen nukleotida. RT-PCR menggunakan sepasang primer spesifik yang mengamplifikasi gen protein selubung PeVYV berhasil mengamplifikasi fragmen DNA berukuran 650 pb. Analisis sikuen nukleotida dari produk RT-PCR menunjukkan bahwa isolat virus penyebab penyakit kuning adalah PeVYV. Penelitian ini merupakan laporan pertama infeksi PeVYV pada tanaman lain selain cabai.
Keyword: Laporan pertama, Polerovirus, reverse transcription-polymerase chain reaction, sikuen nukleotida

Judul: Deteksi Pepper vein yellow virus (PeVYV) Penyebab Penyakit Daun Merah pada Tanaman Wortel di Jawa Barat
Abstrak: Red leaf disease (RLD) is a new reported virus disease on carrot in Indonesia. The disease was characterized by reddening of leaves without any retardation of plant development. The disease was resemble to „carrot motley dwarf (CMD)‟ reported worldwide. Although the symptom likely to be similar, these two diseases were caused by two different viruses. CMD was caused by infection of Carrot red leaf virus (Polerovirus). Whereas, RLD was induced by other Polerovirus, Pepper vein yellow virus (PeVYV). PeVYV has a narrow host range, limited on chili pepper. A report that PeVYV infect carrot in a field of Cipanas, Cianjur was the first report for the virus having host plant other than chili pepper. In this study, some surveys were conducted to elucidate the occurrence of PeVYV in carrot production centers of West Java. Some carrot plants showing RLD were collected from Cipanas (Cianjur), Lembang (West Bandung), and Cikajang (Garut). Based on reverse trancription-polymerase chain reaction analyses, it was found that PeVYV has been already occurred in the areas. The fact that all samples from Garut were infected by the virus suggest that PeVYV may first infected carrot plants in Garut, then spread to other areas of West Java. This is the first report concerning the distribution of PeVYV on carrot crops in West Java.
Keyword: RT-PCR., Production centres, Polerovirus, Distribution

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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