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: Morphological Characterization of Leaf and Flower, and  Fruit Formation Citrus nobilis L. var Madu Derived from Endosperm Culture
Abstrak: Jaringan endosperma jeruk Siam Madu telah berhasil diregenerasikan menjadi tanaman jeruk triploid. Tanaman jeruk Siam Madu triploid diharapkan bisa memproduksi buah seedless. Penelitian bertujuan menginformasikan karakteristik morfologi daun dan bunga, serta pembentukan buah dan biji pada tanaman jeruk hasil kultur endosperma. Penelitian dilaksanakan di KP Pacet BB Biogen Cianjur, Laboratorium Sitologi Balithi Segunung, dan Laboratorium Kultur In Vitro BB Biogen Cimanggu pada bulan Agustus 2021-Juni 2022. Bahan penelitian berupa enam klon jeruk hasil kultur endosperma dan siam diploid. Penelitian terdiri atas tiga percobaan, yaitu karakterisasi morfologi dan anatomi stomata daun, morfologi bunga dan viabilitas serbuk sari, serta pembentukan buah dan biji pada tanaman jeruk hasil kultur endosperma. Hasil penelitian menunjukkan bahwa morfologi daun dan bunga dari enam klon jeruk bervariasi pada ukuran lamina, jumlah kloroplas, panjang pistil terhadap stamen, dan viabilitas serbuk sari. Kombinasi panjang pistil terhadap stamen dan viabilitas serbuk sari yang rendah mengindikasi adanya mekanisme pembentukan buah seedless. Perlakuan penyerbukan sendiri secara signifikan meningkatkan persentase pembentukan buah seedless pada klon jeruk triploid. Diantara klonklon yang diuji, klon TR47 berpotensi untuk dikembangkan menjadi klon jeruk seedless karena memiliki persentase pembentukan buah seedless yang lebih tinggi dibandingkan klon lainnya.
Keyword: number of chloroplasts, pollen viability, self-pollination, seedless fruit, triploid citrus plant

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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