Judul: Analisis Jumlah Kromosom Biji Ungu Hasil Persilangan Jagung Varietas Pulut dengan BC2 Putatif Penginduksi Haploid dan Hasil Perlakuan Kolkisin
Abstrak: Bulbosum method is very potential to produce haploid plant of maize. The development of Bulbosum method in Indonesia was done until initial step, that is cross between local variety with haploid inducer line. This research was conducted to analyze the chromosome number of purple seed from a cross between Pulut and BC2 putative haploid inducer and from in vitro colchicine treatment. The chromosome number of these purple seed were found not haploid (x=10) but diploid (2n=2x=20). The effect of colchicine with different concentrations and durations of treatment to ploidy level was not be able to be observed, because death happened at almost all of the seeds and seedlings treated. Chromosome doubling was found at treatment of seedling root by colchicine concentration of 0.06% for 6 hours, that is became tetraploid (2n=4x=40), but the plant could not survive until planting in greenhouse. The only plant survived after colchicine treatment until planting in greenhouse was still diploid with morphological and anatomical characters which were not different from control plants.
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Judul: Pembentukan Tanaman Haploid Ganda dengan Perlakuan Oryzalin Secara In Vitro pada Biji Jagung (Zea mays) Diduga Haploid
Abstrak: BC2 maize purple kernels estimated haploid were resulted from a cross between Bisma variety with haploid inducer line (3490) by backcross. Chromosome doubling to these kernels was done to produce doubled haploid plants (pure lines). This study was conducted to get an in vitro diploidisation method by oryzalin treatment as a chromosome doubling agent, with concentration of 0, 5, 10, and 15 mM for 24 hours on seeds and root of seedlings. Chromosome analysis on the control of purple kernels showed 66.7% of the seeds was haploid and 33.3% was diploid. Oryzalin treatment affected in doubling the chromosome number from haploid to doubled haploid or from diploid to tetraploid. The higher concentration of oryzalin increased the opportunity of chromosome doubling, but increased death rate. Combination of treatment that is most efficient was 5 mM oryzalin on seedling roots that produced the highest number of doubled haploid plants was found by 71.4% with a low mortality rate by 30%. Increasing of the chromosome number caused the growth of the longer canopy length and more number of leaves and the lower stomata density.
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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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