Judul: Approach Grafting Technique on Kandel  Cultivars of Jackfruit (Artocarpus heterophyllus Lam.)
Abstrak: Teknik sambung susu merupakan teknik grafting dengan kondisi batang atas dan batang bawah dibiarkan tetap berada pada perakaran masing-masing, sehingga suplai hara menjadi lebih banyak. Nangka (Artocarpus heterophyllus Lam.) merupakan tanaman multiguna karena hampir seluruh bagian tanaman dapat dimanfaatkan, seperti buah muda, buah masak, bahkan kulit buah yang sudah menjadi limbah. Nangka kultivar Kandel memiliki keunggulan daging buah lebih tebal, tingkat kemanisan buah lebih tinggi, serta tekstur daging buah yang lebih krispi. Penelitian bertujuan mendapatkan informasi mengenai kompatibilitas batang atas (scion) dan batang bawah (rootstock) pada bibit nangka untuk pertumbuhan optimal hasil grafting. Penelitian menggunakan Rancangan Acak Lengkap (RAL) satu faktor dengan 3 taraf perlakuan berupa perbedaan umur batang bawah yaitu 3, 6, dan 9 BST, dengan masing-masing perlakuan terdapat 6 ulangan. Perbedaan umur batang bawah berpengaruh terhadap persentase kesegaran tanaman dan diameter batang bawah. Namun tidak terdapat perbedaan yang signifikan pada karakter agronomi batang atas dan diameter batang atas., Approach grafting is a grafting technique where the scion and rootstock are allowed to remain on their respective roots, so that the nutrient supply becomes greater. Jackfruit (Artocarpus heterophyllus Lam.) is a multipurpose plant because almost all parts of the plant can be used, such as young fruit, ripe fruit, and even fruit skin that has become waste. The Kandel jackfruit cultivar has the advantage of thicker flesh, a higher level of fruit sweetness, and a crisper flesh texture. The research aims to obtain information regarding the compatibility of scion and rootstock in jackfruit seedlings for optimal growth as a result of grafting. The research used a one-factor Completely Randomized Design (CRD) with 3 treatment levels in the form of differences in rootstock age, namely 3, 6 and 9 MAP, with 6 replications for each treatment. Differences in the age of the rootstock affect the percentage of plant freshness and the diameter of the rootstock. However, there were no significant differences in the agronomic characteristics of the scion and scion diameter.
Keyword: kompatibilitas, batang atas, batang bawah, umur bibit

Judul: Validation of Microsatellite Markers in Several Jackfruit (Artocarpus heterophyllus Lam.) Accessions and Their Relatives
Abstrak: Nangka (Artocarpus heterophyllus Lam.) merupakan salah satu tanaman buah yang tergolong dalam genus Artocarpus. Di wilayah Indonesia terdapat 34 spesies tanaman dari genus Artocarpus yang berpotensi dikembangkan. Keragaman serta potensi tanaman dari genus Artocarpus, menjadikan informasi mengenai marka mikrosatelit penting diketahui sebagai salah satu penanda molekuler. Oleh sebab itu, penelitian ini bertujuan memvalidasi marka mikrosatelit pada beberapa aksesi nangka (Artocarpus heterophyllus Lam.) dan kerabatnya. Penelitian ini dilaksanakan di Laboratorium Seed Center Departemen Agronomi dan Hortikultura Institut Pertanian Bogor pada bulan Desember 2023 hingga Mei 2024. Pada penelitian ini digunakan 23 sampel tanaman dari genus Artocarpus, terdiri dari 7 aksesi nangka (Artocarpus heterophyllus Lam.) dan 16 spesies kerabatnya. DNA dari 23 sampel di amplifikasi menggunakan enam primer marka SSR. Ekstraksi DNA dilakukan dengan metode CTAB yang dimodifikasi dengan penambahan mercaptoethanol. DNA hasil ekstraksi kemudian diuji kuantitas dan kualitasnya sebelum dilakukan proses amplifikasi DNA. Evaluasi kemunculan pita pada gel elektroforesis diduga bahwa terdapat satu primer monomorfik diantara enam primer yang digunakan., Jackfruit (Artocarpus heterophyllus Lam.) is one of the fruit plants belonging to the genus Artocarpus. In Indonesia, there are 34 species of plants from the genus Artocarpus that have the potential to be developed. The diversity and potential of plants of the genus Artocarpus, making information about microsatellite markers is important to know as one of the molecular markers. Therefore, this study aims to validate microsatellite markers on several accessions of jackfruit (Artocarpus heterophyllus Lam.) and its relatives. This research was conducted at the Seed Center Laboratory of the Department of Agronomy and Horticulture, Bogor Agricultural University from December 2023 to May 2024. In this study, 23 plant samples from the genus Artocarpus were used, consisting of 7 accessions of jackfruit (Artocarpus heterophyllus Lam.) and 16 species of its relatives. DNA from 23 samples was amplified using six SSR marker primers. DNA extraction was carried out using the modified CTAB method with the addition of mercaptoethanol. The extracted DNA was then tested for quantity and quality before the DNA amplification process. Evaluation of band appearance on gel electrophoresis indicated that there was one monomorphic primer among the six primers used.
Keyword: amplifikasi, Artocarpus, DNA, elektroforesis, SSR

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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