Judul: Induksi embriogenesis somatik dan seleksi in vitro empat genotipe kedelai untuk toleransi terhadap cekaman aluminium
Abstrak: Soybean (Glycine max (L.) Merr.) is an important source of protein for many Indonesian and the demand of soybean for food is increasing year by year. The increasing demand of soybean is not met by national production mainly due to decreasing harvest area. Therefore, expansion of soybean harvested area should be the main priority in the effort to increase soybean production. However, the targeted area should not be in competition with the other more profitable crops such as corn and rice. Dry acid soil, the main marginal lands in Indonesia, can be developed as an expansion of soybean planting areas because of the area reach 102.8 million hectares. Efficient crop improvement programs should be targeted to generate high yielding soybean varieties grown in acid soil. Currently, more than sixty varieties of soybean have been released by the Ministry of Agriculture, however, few are tolerant to acid soil. The constraint in developing soybean varieties for adaptation to adverse environmental condition is low genetic variability. Genetic variability can induced by conventional and non conventional plant breeding. In vitro selection is one strategy from non conventional plant breeding to produce plants that can be use as a source of variation in a breeding program. The use of somatic embryo for in vitro selection program is very valuable since the selected traits will be inherited in the progenies. Embryogenesis somatic was reported to be genotype specific for soybean. The general objective of this research was to obtain soybean promising lines tolerant to Al toxicity. Specifically, this study was aimed to obtain the optimum medium for induction and proliferation of somatic embryo, and to regenerate embryogenic callus of four soybean genotypes; and to obtain tolerant Al somaclones (putative). This study consisted of two experiments, which was induction of somaclonal variation of four soybean genotypes via somatic embryogenesis and in vitro selection of four soybean genotypes using AlCl3 to generate a putative somaclone acid soil tolerant. Embryogenic callus was obtained from the experiment of optimation of embryogenic callus induction medium. Induced callus had morphological differences, color and diameter in each type of media being used and the type of genotypes. The morphology of the formed callus can be classified into six groups. Callus can be induced at 6 weeks after treatment (WAT) on MS medium with the addition of 10 mg/l 2,4-D and 10 mg/l NAA in all soybean genotypes. Callus induced on medium with 5 mg/l NAA had callus morphology that tends to be green and then rooted. Callus induced on MS medium with the addition of 40 mg/l 2,4-D tends to had compact callus. In MS medium containing 40 mg/l 2,4-D, 54.5% of the Tanggamus genotype callus was embryogenic. Tanggamus genotypes was the only genotype that successfully formed somatic embryo (globular, torpedo and cotyledonary stages) after cultured for 4 weeks in medium containing 40 ppm 2,4-D and subcultured for another 4 weeks in the same media. The other genotype (Willis) formed only preembryonic mass (PEM) and failed to form somatic embryo after cultured in four different induction mediums. In order to increase the number of somatic
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Judul: Seleksi In Vitro untuk Toleransi terhadap Cekaman Kekeringan pada Kedelai (Glycine max [L.l Merr.) dan Karakterisasi Varian Somaklonal yang Toleran.
Abstrak: Penelitian ini bertujuan untuk: (1) memperoleh prosedur yang untuk menginduksi pembentukan embrio somatik primer dan sekunder serta regenerasi tanaman kedelai (2) mengembangkan metode seleksi in vitro untuk toleransi terhadap cekaman kekeringan. (3) mengevaluasi keberadaan varian somaklonal untuk karakter morfologis dan karakter agronomis diantara populasi tanaman kedelai hasil seleksi in vitro dalam media selektif dengan (4) mengidentmkasi tanaman varian somak/onal yang toleran kekeringan, dan (5) mengevaluasi karakter fisiologis somak/onal toleran terhadap kekekeringan.lnduksi dilakukan dengan mengkultur kotlledon muda pada medium MS yang mengandung 2,4-D dan NAA. Seleksi in vitro untuk toleransi terhadap cekaman kekeringan dilakukan dengan memaparkan pada media selektif yang mengandung polyethylene glycol 6000 secara langsung pada konsentrasi PEG sub-Ietal (LO>95%) atau secara bertahap dan konsentrasi PEG rendah konsentrasi sub-leta!. Tanaman SC1 hasil seleksi in vitro dan tanaman turunan SC1 dievaluasi untuk morfologis dan Identmkasi varian yang toleran dilakukan dengan mengamati pertumbuhan tanaman SC2 pada kondisi dengan pengurangan pemberian air di rumah plastik. Untuk mengetahui respon fisiologis tanaman varian somaklonal yang toleran kekeringan dilakukan analisis kandungan pralln dan gula total. Embrio somatik primer dapat diinduksi dari kotiledon muda yang dikultur pada media MS dengan 2,4-0 10 mgll NAA 10 mg/l. Namun demikian untuk pembentukan yang berkelanjutan dilakukan dengan menanam kotiledon muda pada media MS yang mengandung 40 mg/l diikuti dengan menanam primer pada media MS yang mengandung mg/l dan NAA 10 mg/l. Regenerasi plantlet dapat dilakukan dengan menanam pada media maturasi yang mengandung arang aktif 1 gIl selama 1 bulan, selanjutnya ES yang telah masak ditumbuhkan dalam media Yz MS yang mengandung GA3 2 mgll dan 8AP 2mg/1 1 minggu. Penambahan PEG dalam media secara umum menghambat pertumbuhan dan perkembangan ES. Respon pertumbuhan dalam selektif berkorelasi dengan tingkat toleransi genotipenya terhadap kekeringan. Genotipe kedelai yang toleran kekeringan tumbuh lebih baik dalam media selektif dengan PEG dibandingkan dengan genotipe yang Seleksi in vitro untuk toleransi terhadap cekaman kekeringan dilakukan dengan menanam embrio somatik pada konsentrasi sub-Ietal 20%. Tanaman hasil in vitro menunjukkan variasi untuk karakter morfologis dan agronomis. 8eberapa karakter tersebut dikendalikan oleh karena sifat tersebut diturunkan generasi SC1 ke generasi tanaman SC2 pada kondisi kekeringan akibat pengurangan pemberian air di rumah plastik juga menunjukkan adanya varian somaklonal yang toleran kekeringan diantara somaklon yang diuji. Dari penelitian ini dihasilkan dengan toleransi kekeringan yang meningkat dibandingkan dengan kontrol tetua (SCO) yaitu 55% pada genotipe 83731, 11 % pada MLG2999 dan 33% MSC8606. Metode seleksi bertahap dan seleksi langsung sub-Ietal menghasilkan somaklonal yang sama. Varian somaklonal kering menunjukkan akumulasi prolin lebih tinggi dibandingkan somaklonal namun demikian kandungan total somaklonal peka tidak menunjukkan perbedaan. Hasil ini telah berhasil dikembangkan rnt:ll,~nI'IA SE~leI<SI in vitro untuk toleransi terhadap cekaman kekeringan. Metode ini digunakan sebagai model untuk mendapatkan tanaman dengan kekeringan. Varian kekeringan yang diperoleh dalam ini dapat digunakan donor untuk sifat toleran kekeringan atau d&pat varietas baru hasHnya.
Keyword: somatic embryogenesis, drought tolerant, somacional variation, selective medium, proline, sugar

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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