Judul: Yield Test Strain Mutant Elephant Grass (Pennisetum purpureum Schumach) in Lowlands
Abstrak: Rumput gajah (Pennisetum purpureum Schumach) cv. Ciawi Dua merupakan salah satu tanaman pakan ternak yang banyak dikembangkan di Indonesia sebagai sumber hijauan pakan ternak ruminansia. Namun demikian rumput jenis ini belum bisa beradaptasi baik pada lingkungan kekeringan tinggi yang umumnya terjadi di daerah dataran rendah sehingga daya hasil hijauan menurun karena kondisi lingkungan fisik tanah dan iklim yang tidak mendukung. Penelitian ini bertujuan untuk mengetahui potensi keunggulan galur-galur mutan rumput gajah. Bahan tanam yang diuji dalam penelitian ini adalah 7 galur mutan rumput gajah koleksi BB Biogen dan 1 galur mutan rumput gajah kultivar Ciawi Dua sebagai kontrol. Percobaan dilaksanakan di Dusun Ceruk Dendeng, Desa Lulut, Kecamatan Klapanunggal, Kabupaten Bogor, Jawa Barat dari bulan Juni sampai Oktober 2020. Variabel yang diamati adalah jumlah anakan, panjang batang, tinggi tanaman, jumlah daun, panjang daun, lebar daun, panjang ruas, diameter batang, bobot panen per tanaman, dan bobot panen total. Rancangan yang digunakan adalah rancangan kelompok lengkap teracak (RKLT) dengan satu faktor yaitu galur mutan. Hasil penelitian menunjukkan bahwa galur mutan kontrol/asli secara umum lebih baik daripada galur-galur mutan rumput gajah hasil pemuliaan in vitro berdasarkan seluruh aspek pengamatan. Galur M6 dan M5 berpotensi untuk dikembangkan lebih lanjut karena memiliki karakter yang lebih baik dibanding galur lainnya selain galur kontrol., The elephant grass (Pennisetum pupureum Schumach) cv. Ciawi Dua is one of the most developed forage crops in Indonesia as a source of feed for ruminants. However, this grass has not been able to adapt well to the drought environment which generally occurs in lowland areas so that crop yields can decrease due to unfavorable physical soil and climatic conditions. This study aimed to determine the potential advantages of elephant grass mutant lines. The genetic materials tested in this study were 7 mutant lines of BB Biogen elephant grass collection and 1 mutant line of elephant grass cultivar Ciawi Dua as a control. The experiment was carried out in Ceruk Dendeng Hamlet, Lulut Village, Klapanunggal District, Bogor Regency, West Java from June to October 2020. The variables observed were number of tillers, stem length, plant height, number of leaves, leaf length, leaf width, internode length, stem diameter, sample harvest weight, and total harvest weight. The research design used was a completely randomized group design with one factor, namely mutant line. The results showed that the control/native mutant lines were generally better than the elephant grass mutant lines from in vitro breeding based on all aspects of observation. Two lines have the potential to be developed further because they have better characters than other lines besides control line.
Keyword: mutant line, forage, elephant grass

Judul: Preliminary Yield Test of Several Mutant Lines of  Situgintung Upland Rice in Dry Land
Abstrak: Peningkatan jumlah penduduk setiap tahun menuntut adanya peningkatan produksi padi untuk memenuhi kebutuhan pangan. Budidaya padi gogo menjadi upaya yang dapat dilakukan untuk meningkatkan produksi padi di Indonesia dengan mengoptimalkan penggunaan lahan kering. Penelitian ini bertujuan untuk mengidentifikasi daya hasil dan komponen hasil dari 10 galur mutan padi gogo Situgintung. Penelitian dilaksanakan di Kebun Percobaan Pusat Riset Teknologi Proses Radiasi (PRTPR), ORTN-BRIN, Lebak Bulus, Jakarta Selatan pada bulan Januari hingga Agustus 2023. Penelitian ini menggunakan faktor tunggal yaitu genotipe sebagai perlakuan yang disusun dalam rancangan kelompok lengkap teracak dengan 3 ulangan. Uji beda nyata jujur digunakan untuk mengetahui perbedaan antar perlakuan. Hasil penelitian menunjukkan bahwa seluruh galur mutan yang diuji memiliki produktivitas yang sama dibandingkan dengan dua varietas pembanding Limboto dan Situgintung, kecuali galur G107 dan G29 yang lebih tinggi dibandingkan kedua varietas pembanding serta galur G229 juga nyata lebih tinggi dibandingkan dengan varietas Situgintung. Beberapa karakter menunjukkan korelasi positif terhadap produktivitas galur mutan padi gogo, meliputi lebar daun bendera, panjang batang, jumlah anakan produktif, jumlah anakan total, jumlah gabah bernas, persentase gabah bernas, jumlah gabah total, dan kerapatan gabah per malai. Karakter yang berkorelasi negatif terhadap produktivitas adalah persentase gabah hampa., The increase in population every year demands an increase in rice production to fulfill food needs. Upland rice cultivation is an effort to enhance rice production in Indonesia by optimizing dry land use. This study aimed to identify the yield capacity and yield components of 10 mutant lines of Situgintung upland rice. The research was carried out at the Experimental Station of the Radiation Process Technology Research Center (PRTPR), ORTN-BRIN, Lebak Bulus, South Jakarta from January to August 2023. This experiment used a single factor, namely genotype as treatment, which was arranged in a randomized complete group design with 3 replications. The honest significant difference test was used to determine differences between treatments. The results showed that all the mutant lines tested had the same productivity compared to the two check varieties Limboto and Situgintung, except for lines G107 and G29 which were higher than the two check varieties, and lines G229 which was higher than Situgintung varieties. Several characters showed a positive correlation with the productivity of upland rice mutant lines, including flag leaf width, stem length, number of productive tillers, total number of tillers, number of pithy grains, percentage of pithy grains, total grain number, and grain density per panicle. Characters that have a negative correlation with productivity was the percentage of empty grain.
Keyword: Mutant lines, productivity, upland rice

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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