Judul: Studi Poliembrioni, Viabilitas Benih dan Identifikasi Genetik Semaian Jeruk Japansche Citroen (Citrus limonia Osbeck.) menggunakan SSR
Abstrak: Japansche Citroen (Citrus limonia Osbeck) or JC is citrus rootstock that is often used by Indonesian citrus farmer because its wide adaptation ability and has resistant to several diseases. JC seeds should have physical, physiological, genetic and health quality. Seed has maximum quality when it is reached at the time of physiological maturity. Seed maturity, in general is decided by physical appearance of fruit, such as rind colour changes. JC seeds have polyembryony characteristic; threrefore one or more embryos per seed consist of either zygotic embryo and or nucellar embryo. Nucellar embryo can be useful for clonal propagation. Nevertheles, there were off type seedling. It is necessary to identify seedling base on morphology and molecular marker such as SSR marker. Morphology marker was easy to used and cheap, but the trully genetic must be identify with SSR. SSR could differenciate between homozygot and heterozigot genotype. The aims of this research were to acquire information about poliembryony on JC citrus, to determine physiological maturity of JC seed base on rind colour and fruit hardness, to know the effect of fruits maturity to physical and physiological quality of seed, genetic quality and number of seedling, and to identify JC seedling base on morphology marker and SSR marker. The research was conducted in Indonesian Citrus and Subtropical Fruits Research Institute from April 2012 to January 2013. The research consisted of three experiments, there were 1) study on polyembryony of JC , 2) study on effect of fruits maturity level to physical and physiological quality of seed, genetic quality and number of seedling, and 3) identification of JC seedling base on morphology marker and SSR marker. Experiment I was conducted based on visual observations on each of 30 seeds of five maturity levels. Criteria of fruit maturity are 1) dark green rind, hard fruit (> 7 kg/cm2), 2) green yellow rind, rather hard (6-7 kg/cm2), 3) pieces of yellowish green rind, rather soft (5-5.9 kg/cm2), 4) >90% yellow rind, soft (4-4.9 kg/cm2) and 5) pieces of yellow-orange rind, very soft (< 4 kg/cm2). The experiment variable were seed coat colour, the mean number of embryos per seed, polyembryony seed percentage (%) and the dominant colour of the embryo. Experiment II used randomized completely block design (RCBD) one factor. The factor is five maturity level base on fruits maturity. The criteria of fruits maturity are equal to experiment I. Each treatment was repeated three times so that there was 15 units of experiments with experimental unit consisted of 100 seeds. The experiment variable were seed moisture content (%), dry weight of 10 seeds (g), vigor index (%), seed growth rate (%/etmal), germination percentage (%), the growth percentage (%), multiple seedling percentage (%), total seedlings, off type seedling percentage (%), and total true to type seedling. Data were analyzed with analysis of variance (ANOVA). If the results obtained by analysis of variance were significant different, then tested by Duncan's Multiple Range Test (DMRT) at 5% level. Experiment III was the identification of true to type seedlings and off type seedling with morphology marker and molecular markers. This experiment
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Judul: Morphological Characterization and Fruit Formation in Polyploid Citrus Plants Resulting from Somatic Hybridization and Endosperm Culture
Abstrak: Target pemuliaan tanaman jeruk adalah mendapatkan buah jeruk seedless yang lebih disukai oleh konsumen. Pembentukan buah jeruk seedless dapat terjadi akibat adanya sifat partenokarpi alami dan perpasangan tiga set kromosom yang tidak seimbang pada buah triploid. Karakterisasi morfologi perlu dilakukan untuk mengidentifikasi karakter-karakter unggul yang tampak, terutama karakter yang berkaitan dengan pembungaan dan pembentukan buah untuk memastikan apakah galur jeruk poliploid khususnya triploid dapat menghasilkan buah seedless. Penelitian yang dilakukan terdiri dari karakterisasi morfologi habitus, daun, bunga, buah, dan biji, serta induksi pembentukan buah dan biji pada galur jeruk poliploid hasil hibridisasi somatik dan kultur endosperma. Hasil penelitian menunjukkan bahwa hampir semua karakter morfologi galur hasil hibridisasi somatik dan kultur endosperma mewarisi tetua jeruk siam madu, kecuali beberapa karakter morfologi bunga yang mewarisi kedua tetuanya, yaitu jeruk siam madu dan mandarin satsuma. Perlakuan penyerbukan sendiri secara nyata dapat meningkatkan persentase pembentukan buah seedless pada galur jeruk poliploid, baik pada galur hasil hibridisasi somatik maupun hasil dari kultur endosperma. Galur FS25 berpotensi untuk dikembangkan menjadi salah satu galur jeruk seedless karena memberikan hasil persentase pembentukan buah seedless tertinggi dibanding galur lainnya. Galur MT12 menunjukkan adanya perkembangan biji triploid yang terbentuk secara spontan., The target of citrus breeding is to obtain seedless citrus fruit that are preferred by consumers. The formation of seedless citrus fruits can occur due to the natural parthenocarpy and the unbalanced pairing of three chromosome sets in triploid fruits. Morphological characterization needs to be done to identify the superior characters, especially those related to flowering and fruit formation to determine whether polyploid citrus lines, especially triploids can produce seedless fruit. The research consisted of characterization the morphology of the habitus, leaves, flowers, fruit and seeds, as well as the formation of fruit and seeds in the polyploid citrus line resulting from somatic hybridization and endosperm culture. The results showed that almost all morphological characters of the lines resulting from somatic hybridization and endosperm culture were inherited from the parents of siam madu, except for several morphological characters of flowers inherited from the parents of siam madu and satsuma mandarin. The self-pollination treatment significantly increased the percentage of seedless fruit formation in the triploid citrus line. The FS25 line can be developed into one of the seedless citrus lines because the percentage of seedless fruit formation higher than other lines. The MT12 line showed triploid seed development which spontaneously formed.
Keyword: endosperm culture, morphological characterization, pollination, seedless fruit, somatic hybridization

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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