Judul: Eksplorasi Marka Mikrosatelit yang Terkait dengan Sifat Toleransi Keracunan Aluminium pada Padi
Abstrak: Acid soils limited agricultural productivity around the world because of the high solubility of aluminum (Al). The objective of this study was to find gene location of Al tolerant trait in rice chromosome from crossed between Cabacu and IR64. One way to found gene location of Al tolerant was by using phenotype analysis and molecular marker microsatellite or SSR (Simple Sequence Repeats). Markers with a specific character could be selected using Bulk Segregant Analysis (BSA). Total 187 strains of F6 rice population from crossed between Cabacu and IR64 were tested using solution of Yoshida. Root length at 45 ppm AlCl3 condition for 21 days was used as data for phenotype linkage analysis with molecular markers. The result of linkage analysis using 47 microsatellite primer shown that RM 104, RM 25, RM 72 and RM 201 were associated with Al stress tolerant trait. These markers shown the genes location which associated with aluminum toxicity tolerance at position 40.166.840 bp chromosome 1, 4.377.460 bp dan 6.762.710 bp chromosome 8 and 20.174.289 bp chromosome 9.
Keyword: tolerant, bulk segregant analysis, microsatellites marker, rice.

Judul: Isolation and characterization of an aluminum tolerance gene in Rice
Abstrak: Aluminum (Al) toxicity is the major limiting factor of crop production in acid soil. Aluminum tolerance in rice is considered as a quantitative trait controlled by many genes. The objectives of this research were to isolate, clone, characterize the aluminum tolerance gene, and to develope codominant marker for rice B11 gene. Plant materials used in this research were four rice genotypes namely Grogol, Hawara Bunar, IR64, and Krowal, and the F2 segregating rice population derived from a cross between Al-sensitive rice genotype IR64 and Altolerant rice genotype Hawara Bunar. A rice Al tolerance gene was isolated based on a combination between rye-rice syntenic relationship and RT-PCR (Reverse Transcription-Polymerase Chain Reaction) approaches. The cDNA of rice Al tolerance gene was synthesized from mRNA isolated from Hawara Bunar after being stressed under 15 ppm Al at pH 4.0 for 24 hours. The Al tolerance gene was characterized by sequencing, bioinformatically analyzing, and introducing it to tobacco plant. The inheritance pattern of rice Al tolerance gene was analyzed by developing the CAPS (Cleaved Amplified Polymorphism Sequence) codominant marker of rice Al tolerance gene through a series of PCR, sequencing, and restriction enzyme analysis of the PCR fragment from IR64 and Hawara Bunar, followed by testing the marker in F2 rice population. This research has succesfully cloned an Al tolerance gene from Indonesian local rice genotype Hawara Bunar, called B11 gene. The B11 gene expression was induced by Al with higher expression level in Hawara Bunar than that of IR64. Transgenic tobacco plants carrying the gene were more tolerant to Al stress than that of nontransgenic tobacco plants. The B11 protein was similar to bacterial ribosomal L32 proteins and was predicted as a transcription factor with bZIP domain and C2H2-zinc finger like motif. Comparison between the B11 gene sequences of the IR64 and Hawara Bunar showed 8 SNPs (Single Nucleotide Polymorphisms). One of the SNPs located at nucleotide 668 causing AluI restriction site based polymorphism between IR64 and Hawara Bunar, which was then used as a basis of B11-CAPS codominant marker development. The marker segregation followed a single gene inheritance pattern. The marker might be used for MAS (Masrker Assisted Selection) in rice breeding programs to obtain Al-tolerant lines.
Keyword: Oryza sativa, Rice breeding, Al tolerance gene, Root re-growth, Transgenic plant, CAPS marker

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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