Judul: Genetic parameters estimation of agronomic and quality traits and selection high yielding sorghum lines in acid soil
Abstrak: Sorghum is a crop that has potential to be developed as an alternative food because sorghum is a source of carbohydrate and the content of protein, calcium and vitamin B1 is higher than corn and rice. Furthermore, sorghum has potency to be developed as raw material for bioethanol. The adaptation of sorghum in dry environment is suitable to be developed on dry land in Indonesia which is dominated by acid soil. The purpose of this study was to obtain genetic parameters of agronomic and quality traits of sorghum in acid soil and to obtain tolerant and high yielding sorghum lines. The study was divided into three experiments conducted at UPTD of Dry Land Tenjo. Genetic material used in experiments 1 and 3 was F4 and F5 generations from crosses between UPCA S1 (sensitive to acid soil) and Numbu (tolerant to acid soil). Genetic material used in the second trial was six mutant lines and four national varieties. The results showed that there was high variation on stem weight, biomass weight, grain weight/plant, total sugar content and harvest index. The variation of the content of amylose, amylopectin and protein was low, while the tannin content showed a wide variation. The result of selection based on grain weight/ plant and biomass weight could potentially generate 14 genotypes tolerant to acid soil and high yielding. Selection based on grain weight/plant and weight of biomass was effective in acid soil.
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Judul: Physiological adaptation of Sorgum (Sorghum bicolor (L.) Moench) to aluminum toxicity and phosphorous deficiency in acid soils.
Abstrak: Sorghum (Sorghum bicolor (L) Moench) is an ideal crop to be developed as food diversification and source of bioethanol in Indonesia because this crop has high adaptability to be grown in dry lands. From a total of 148.2 millions ha dry land in Indonesia, an estimated are of 108 millions ha are acid soil (ultisols). Acid soils have low fertility and Al toxicity which are major constraints for crop production in acid soil. For sorghum production in acid dry lands, sorghum varieties having high adaptation to acid soil have to be developed. The objectives of this study was to obtain complete information about the physiological adaptation to aluminum toxicity and phosphorus deficiency which can be used as the character selection in breeding program to obtain the tolerant sorghum in acid soils. The genotypes used was Numbu (Tolerant), ZH-30-29-07 (Tolerant), B-69 (sensitive) and B-75 (sensitive) from selected on acid soils in Lampung. The study on physiological mechanism of sorghum adaptation to acid soils has resulted in information that the main limiting factor in soghum growth in acid soil was phosphorous deficiency. Under sufficient P, without liming, the sensitive genotype produced similar yield. The tolerant genotype, Numbu and ZH30-29-07 showed higher ability to maintain root growth under Al stress and P deficiency. The tolerant genotypes also showed higher ability to absorp nutient under low P condition compared to sensitive genotypes. The lowest concentration of 74 μM Al can reduce the growth in all genotypes tested. The longer the sorghum roots exposed to the stress, the higher the value of scoring and the accumulation of aluminum in the roots under Al toxicity. Sorghum genotypes had specific absorption rate was high, but it was not followed by increasing of roots length, roots dry weight and shoot dry weight. Specific absorption rate is more affected by Al stress rather than increasing level of P. Genotype ZH-30-29-07 were tolerant in identified in acid soils showed the moderate response to Al toxicity in nutrient solution. The higher aluminum concentration leading to greater plant growth inhibition. The tolerant genotypes had the internal mechanism (tolerance) in the face under low P condition by increasing the efficiency of internal phosphor (interrelated), otherwise the sensitive genotype had the external mechanism (avoidance) through increased P absorption or total P . There was no relationship between the use efficiency of P with total P content of plant both in testing using the acid soils in rhizotron and nutrient solution.
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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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