Judul: Identifikasi Gen Xa pada Galur F1 Code x Angke dan Ciherang x IRBB21 serta Uji Patogenitas Padi Galur Isogenik
Abstrak: Developing of Ciherang varieties using bacterial leaf blight resistance genes (Xa genes) and pathogenicity tests using bacterial isolate Xanthomonas oryzae pv. oryzae collections in 2012 from Central Java toward near-isogenic lines (NILs) have not been reported. Transfer of resistance genes in Ciherang varieties did by cross method and molecular marker. Varieties of Angke crossed with Code because each has a Xa gene, namely xa5 and Xa7 gene. While Ciherang crossed with IRBB21 as Xa21 gene donor. Identification of xa5 and Xa7 genes in Code x Angke were resulted 16 lines have those genes. xa5 gene amplified in 213 bp using SSR marker, while Xa7 gene amplified in 294 bp using STS marker. These DNA size are resistant marker. Identification of Xa21 gene in Ciherang x IRBB21 was resulted 21 lines have this gene. Xa21 gene amplified in 1000 bp using STS marker as resistant marker. The result of pathogenicity tests obtained bacterial isolate whose have highest levels of virulence, that is isolate with the code number Xoo12-183 from Duwet Pekalongan.
Keyword: Xa gene, pathogenicity, paddy Ciherang, near-isogenic lines (NILs), molecular marker

Judul: Deteksi gen ketahanan penyakit Hawar Daun Bakteri pada populasi silang ganda F1 (DCF1) padi Ciherang
Abstrak: Xanthomonas oryzae pv. oryzae causes leaf blight has many strains and volatile form a new strain. A result that was initially resistant rice varieties may turn out to be sensitive. Improvement Ciherang using gene pyramiding bacterial leaf blight resistance will carry different resistance and has a broad spectrum. This research aims to detect the 207 individual DCF1 Ciherang results gene pyramiding using SSR markers and STS. Four individuals have acquired genes Xa4+xa5+Xa7+Xa21 that is DCF1Ch|CA-42, DCF1Ch|CA-69, DCF1Ch|CA-162, DCF1Ch|CA-163, 11 individuals have genes xa5+Xa7+Xa21, 46 individuals have xa5+Xa21 gene, 31 individuals have Xa7+Xa21 gene, and 45 individual have genes xa5+Xa7. Agronomic characters panicle number DCF2 Ciherang not significantly different from the parent and panicle length DCF2 Ciherang did not differ significantly with parent. Weight of filled grain DCF2 Ciherang significantly greather than the parent. Weight of empty grains DCF2 Ciherang also significantly different from the parent, greather than elders Code, Angke, Ciherang, and IRBB21.
Keyword: Bogor Agricultural University (IPB), pyramiding genes., rice Ciherang, double cross, bacterial leaf blight

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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