Judul: Pengaruh perlakuan rizobakteri pada benih dan tanaman serta pemupukan fosfat terhadap pertumbuhan tanaman tetua betina jagung hibrida
Abstrak: The use of quality seeds from improved varieties will produce plants more productive and efficient. Seed quality constitute of genetic, physical, physiological, and health quality. Phosphate fertilizer can enhance plant growth, however only 10-30% of fertilizer P that can be absorbed by plants. The use of rhizobacteria can enhance phosphate uptake and plant growth. The objectives of this study were to improve the quality of physiological seeds and plant growth hybrid corn using rhizobacteria and phosphate fertilizers. The research has conducted in three stages of experiments in the laboratory, greenhouse and in the field. Experiment used parent of hybrid corn seed cv. Bima-3, namely: Nei9008 (female parent) and Mr14 (male parent). The groups of isolates Actinomycetes, Bacillus spp. and fluorescent pseudomonads are used in these experiments. The experiment steps were: (1) characterization and screening of rhizobakteria, (2) Evaluation of selected rhizobacteria on seed quality and seedling growth of female parent and (3) Effect of rhizobakteria treatment and phosphate fertilizer on plant growth of female parent. Experiment 3 were conducted in two seasons, season I using six isolates selected from Experiment 1 and 2, while the season II using two isolates which indicated the best result from season I. In the field experiment, the seeds has planted in polybags with sterilized soil. Experiment 3 was arranged in Split Plot Design. The main plot consisted of five doses of phosphate fertilizer, which is 0, 75, 125, 175, and 200 kg SP-36/ha (100% of recommended dosage). Subplot is rhizobacteria treatment. The results showed, there were five isolate choosed from 10 isolates of each genus of rhizobacteria based on the criteria of high producing phosphatase, negative hypersensitive reaction test, producing IAA and chitinase. Experiment 2 showed the rhizobacteria B28 and B46 increase growth rate and seed vigor index. The results of Experiment 1 and 2, rhizobacteria AB2, ATS4, B28, P14 and P31 was selected based on the ability to improve the physiological seed quality of female farent and rhizobacteria B42 based on the highest production of IAA (14.4 μg/ml). Field experiment at the season I, there were rhizobacteria ATS4 and B28 increased plant growht compare to other rhizobacteria. The results from season II, ATS4 has potential to promote plant growth with average number of leaf and plant height at 4 weeks after planting 5.2 and 56.88 cm compared to control 4.8 and 55.98 cm respectively. Phosphate fertilizer strongly influenced on the average number of leaves and plant height. In the season II at 2 and 4 weeks after planting, fertilizing with the recommended dose (200 kg SP-36/ha) showed highest average the number of leaves and the plant height compared with other treatments.
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Judul: Evaluasi Kemurnian Genetik dengan Marka Mikrosatelit dan Aplikasi Rizobakteri untuk Meningkatkan Produksi dan Mutu Fisiologis Benih Jagung Hibrida
Abstrak: One effort to improve maize production is through the use of high quality maize seed. In order to assure high quality seed, it’s genetic quality must be tested. SSR markers often used in genetic studies of maize plants. Therefore SSR can be used to analyze the genetic purity of maize hybrid seed. Another effort to increase productivity and physiological quality of maize hybrid seeds is using rhizobacteria and phosphate fertilizer. The objectives of this research were 1) to determine SSR markers specific for male and female parents, 2) to know the effectiveness of SSR markers for the genetic purity testing of maize hybrid seeds, 3) to find non phytopathogenic rhizobacteria isolates capable of dissolving phosphate, producing IAA, and improving the physiological quality of seed and seedling growth of female parent of maize hybrid, 4) to assess the effect of rhizobacteria and phosphate fertilizers to increase plant growth and yield female parent of maize hybrid, 5) to investigate the effect of rhizobacteria and P fertilizer for increasing productivity and physiological quality of maize hybrid seed. This research consisted of four stages: (1) Selection of SSR primers specific for female and male parents, and testing of genetic purity of hybrid maize seed using SSR markers, (2) Characterization of rhizobacteria in producing IAA, dissolving unsoluble forms of phosphate, non phytopathogenic (hypersensitive reaction test), and improving the physiological quality of maize hybrid seed, (3) Testing the effectiveness of rhizobacteria and phosphate fertilizer on plant growth of female parent in polybag, and (4) Evaluation the effectiveness of rhizobacteria and phosphate fertilizer to increase productivity and the physiological quality of maize hybrid seed in the field. All stages of the research were conducted from April 2011 until December 2012. Results of experiment 1 showed that: 1) Out of five markers tested, three markers namely phi96100, phi328175 and phi072 produced polymorphic bands and were able to distinguish parental lines of two maize hybrid varieties. SSR marker phi96100 was specific for detection the genetic purity of cv.Bima-4 and phi072 for cv.Bima-3. While phi328175 was specific markers to both maize hybrids. The genetic purity of cv.Bima-3 and cv. Bima-4 were 97.5% and 80% respectively. Results of experiment 2 showed that from 34 rhizobacteria isolates, consisted of Actinomycetes, Bacillus spp., and Fluorescent pseudomonads, five isolates of each group having characteristic of dissolving phosphate, producing IAA, and non phytopathogenic. B28 and B46 isolates increased growth rate and vigour index of female parent seeds of hybrid maize. AB2, ATS4, B28, P14, and P31 isolates were selected based on the ability to improve the physiological seed quality of female parent and the rhizobacteria B42 based on the highest production of IAA. These isolates were then used in the field experiment. Results of experiment 3 showed that phosphate fertilizer did not effect the plant growth, weight of ear, and weight kernel per ear but rhizobacteria B42 isolate was potential to increase plant growth compared the control and other rhizobacteria. B28 isolate was potential to increase weight of ear, and weight kernel per ear. Results of the field experiment showed that at the first planting season (rainy
Keyword: Actinomycetes, Fluorescent pseudomonads, parental lines of maize hybrid, seed storage, SSR 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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