Judul: Identifikasi Xanthomonas oryzae pv. oryzae dengan Teknik Biomolekuler dan Karakter Patogenitas terhadap Padi Galur Isogenik.
Abstrak: Increased production of paddy can face obstacle because the biotic stresses like bacterial leaf blight (BLB). The aim of this research to identification BLB caused by Xanthomonas oryzae pv oryzae (Xoo) by biomolecular technique using three primers specific Xoo through PCR colony, and to know virulence of Xoo isolates from West Java, West Sumatera, West Borneo by clip method for character of pathogenicity analysis using near-Isogenic lines and popular varieties. The purifying result were obtained 72 isolates namely 20 isolates from West Java, 30 isolates from West Sumatera, 22 isolates from West Borneo. Most of isolates were identified Xoo positive, except isolate Xoo11-023 from West Sumatera were identified Xoo negative. The character of pathogenicity showed that Code which contain resistant gene Xa4-Xa7 and IRBB5 which contain resistant gene xa5 were resistant to Xoo from all three areas. The average disease intensity on Code and IRBB5 of isolates from West Java was 1.62 % and 3.55%, West Sumatera was 2.10 % and 2.97 %, West Borneo was 2.17 % and 4.45 %. Isolate Xoo11-042 from West Sumatera was the one having highest virulence with average disease intensity on Code 3.29 % and IRBB5 6.90 % which classified as moderate resistant.
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Judul: Marka Molekuler untuk Mendeteksi Xanthomonas oryzae pv. oryzae Asal Jawa Barat dan Karakterisasi Patogenik Secara In Vivo
Abstrak: ra In Vivo. Dibimbing oleh SURYANI dan A. ZAENAL MUSTOPA Hawar daun bakteri (HDB) adalah penyakit serius pada padi yang dapat mengurangi hasil panen. Penyakit ini disebabkan oleh bakteri Xanthomonas oryzae pv oryzae (Xoo). Upaya yang telah dilakukan untuk mengendalikan HDB diantaranya penggunaan antibiotik, kombinasi pupuk, sanitasi, kombinasi antagonis Pantoea agglomerans, Pseudomonas fluorescens, dan Bacillus subtilis dan penggunaan varietas tahan HDB. Meledaknya kasus HDB di Indonesia khususnya Jawa Barat, maka perlu dilakukan peninjauan dan evaluasi kembali penyakit ini agar dapat dilakukan penanganan yang tepat. Penelitian ini bertujuan mendeteksi Xoo asal Jawa Barat dengan menggunakan marka molekuler dan mengetahui tingkat virulensinya dengan karakterisasi patogenik secara in vivo. Tahapan penelitian yang dilakukan adalah isolasi bakteri Xoo berdasarkan morfologinya, deteksi bakteri dengan marka molekuler, dan karakterisasi patogenik bakteri Xoo secara in vivo dengan varietas padi yang tahan HDB (IRBB7 dan Conde) dan varietas rentan HDB (IR64 dan TN 1). Hasil identifikasi 240 isolat bakteri penyebab infeksi tanaman padi dari 50 lokasi di Jawa Barat dengan tiga pasang primer spesifik (XO1, Xoo4009, dan Xoo2976) menunjukkan hanya empat isolat yang positif Xoo, yaitu isolat 6D (Cicalengka-Bandung), 17D (Sindang Karya-Karawang), 19D (Rawamerta-Karawang), dan 21D (Teluk Jambe-Karawang). Isolat 6D digunakan untuk analisis lebih lanjut yaitu tahap sequencing yang menunjukkan kemiripan 98 % pada forward dan 96 % pada reverse dengan Xoo PX099A strain Filipina, Xoo MAFF311018 strain Jepang, dan Xoo KACC10331 strain Korea. Karakter patogenitas secara in vivo menunjukkan tingkat kerusakan tertinggi terjadi pada varietas padi TN 1. Varietas IRBB7 dan Conde telah memasuki status agak rentan HDB. Tingkat virulensi tertinggi terjadi pada isolat 6D dan terendah terjadi pada isolat 21D. Intensitas penyakit HDB pada tanaman fase bibit lebih tinggi dibanding dengan fase dewasa.
Keyword: Bacterial Leaf Blight (BLB), morphologic Xoo bacterial isolation, bacterial pathogenicity, Cicalengka-Bandung, Rawamerta-Karawang, Teluk Jambe Karawang

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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