Judul: Keragaman genetik dan adaptabilitas gandum (Triticum aestivum L.) introduksi di lingkungan tropis
Abstrak: The objective of this study was to obtain information on genetic variabilitiy and adaptability of introduced wheat varieties in tropical conditions. The research was carried out at field station research of Balithi, Cipanas and Biotrop, Bogor, Indonesia in May 2010 - February 2011. Genetic material tested was the Oasis/Skauz//4*BCN var -28, HP 1744, Laj/Mo88, and Rabe/M88 (introduced from Turkey), Basribey, Alibey, and Menemen (introduced from India), G-21, G- 18 and H-2 (introduced from CIMMYT), and Selayar and Dewata (national varieties) as check varieties. The results showed that plant height, panicle length, spikelet number, grain weight per panicle and 1000 grain weight had high heritability value. Genotype (G), location (L), and the interaction GXL had significant effect on grain weight. Grain weight variation of introduced wheat varieties was mainly due to interaction between genotype and location. Based on the regression coefficient, Rabe/Mo88 showed good adaptation in the highland (Cipanas), whereas Oasis/Skauz //4 * BCN var-28 had good adaptation in the lowland (Bogor). The first bilinear AMMI model accounted 93.6% variation. Biplot analysis showed that Menemen, Basribey, Alibey, and Selayar classified as stable varieties with high yields, whereas Laj/Mo88 was stable with lower yield than the average yield of all locations. G-18 adapted well in Manado and G-21 to adapt well in Muneng. There was no superior genotype in all locations.
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Judul: Analisis genetik dan seleksi generasi awal segregan gandum (Triticum aestivum L.) berdaya hasil tinggi
Abstrak: The preliminary breeding research series to develop adaptive variety in wheat to low and medium land regions had been conducted. It was started from evaluation and identification of agronomical responses of some introduced varieties, selective hybridization and development the breeding populations, until selection in early generation to identify high yielding potential segregants. First field experiment was conducted at two Indonesian agroecosystems (BIOTROP as low land representative and Cipanas as high land representative) from Mei to September 2011 and others were conducted at Research Station of BALITHI, Cipanas. The first experiment results showed that location had significant effect on wheat performance. High temperature in low land decrease the sink-source capacity, accelerate the seed filling period, and increase the empty floret. The tested genotypes were classified into three tolerance level. Oasis was classified as tolerant genotype, HP1744, LAJ, Menemen, Alibey, Selayar, and Dewata were classified as medium tolerant, and Rabe, H-21, G-21, G-18, and Basribey classified as sensitive genotypes. Analysis of agronomical traits-controlling gene action showed that all of observed traits controlled by poligenic with additive and epistatic effects. The total tillering number, productive tillering number, shoot-root dried weight, seed weight/panicle, and seed number/pland had strong phenotypic correlation with seed weight/plant. On the other hand, based on path analysis only two traits which had high direct effect to seed weight/plant. Those traits are useful for secondary trait in improving yield potential. Four selected traits (seed weight/plants, productive tillering number, seed weight/panicle, ratio of empty floret) had been used to develop an selection index. Selected segregants in Oasis x HP1744 population are O/HP-F2-87, O/HP-F2-93, O/HP-F2-100, O/HP-F2-106, O/HP-F2-51, O/HP-F2-6, O/HP-F2-16, O/HP-F2-124, O/HP-F2-92, O/HP-F2-39, O/HP-F2-9, O/HP-F2-26, O/HP-F2-31, dan O/HP-F2-123. S/R-F2- 39, S/R-F2-13, S/R-F2-61, S/R-F2-19, S/R-F2-56, S/R-F2-7, and S/R-F2-64 are selected segregants in Selayar x Rabe population. In addition selected segregants in Dewata x Alibey population are D/A-F2-34, D/A-F2-13, D/A-F2-99, D/A-F2-22, D/A-F2-70, D/A-F2-4, D/A-F2-33, D/A-F2-80, D/A-F2-25, dan D/A-F2-65. All of the selected segregants have higher phenotypic performance in all observed traits than their parents.
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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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