Judul: Identification of Morpho-Agronomic Characteristics of 48 Inbred Lines of Maize (Zea mays L.)
Abstrak: Pengembangan jagung sangat prospektif karena nilai multigunanya. Pemuliaan jagung merakit varietas hibrida merupakan upaya penting. Keragaman genetik dalam populasi jagung diperlukan untuk menyeleksi calon tetua hibrida. Penelitian ini bertujuan mempelajari keragaman karakter morfologi dan agronomi serta mengidentifikasi galur jagung yang potensial sebagai tetua hibrida. Penelitian dilakukan di Kebun Percobaan Leuwikopo, Dramaga, Bogor, pada September 2023 hingga Januari 2024 menggunakan rancangan kelompok lengkap teracak augmented. Varietas pembanding meliputi BISI-18, JHG02, P21, P27, NK Perkasa, dan NK Sumo dengan enam ulangan, serta 48 genotipe yang diuji. Hasil penelitian menunjukkan genotipe jagung berpengaruh nyata pada hampir semua karakter kecuali anthesis silking interval. Perbedaan nilai tengah ditemukan pada sebagian besar karakter agronomi dan komponen hasil. Keragaman morfologi juga terlihat pada intensitas antosianin pada malai, rambut, dan akar penyangga, serta mengombaknya tepi helaian daun. Seleksi dapat dilakukan pada hampir seluruh karakter kuantitatif karena memiliki nilai heritabilitas arti luas yang tergolong tinggi. Terdapat tiga klaster utama berdasarkan fenotipe. Genotipe dalam klaster 1 seperti L15, NEI, M8, M9, L41s, P13, dan L42 berpotensi dikembangkan sebagai tetua hibrida. Korelasi kuat antara karakter agronomi dan komponen hasil belum ditemukan, korelasi didapati pada beberapa karakter seperti umur berbunga jantan dan betina, tinggi tanaman dan tinggi tongkol serta antar karakter lainnya., The development of corn commodities is promising due to its multifunctional value. Corn breeding to develop hybrid varieties is an important effort. Genetic diversity in corn populations is needed as a source for hybrid breeding. This study aimed to elucidate genetic diversity based on morphological and agronomic characteristics of 48 inbred lines and identify potential lines. The research was conducted from September 2023 to January 2024 at Leuwikopo Experimental Station, Dramaga, Bogor, West Java. The experiment used an augmented randomized complete block design with six replications for the checks. Forty-eight inbred lines were evaluated along with six check varieties BISI-18, JHG02, P21, P27, NK Perkasa, and NK Sumo. The results showed that genotypes significantly influenced all observed traits except the anthesis silking interval. Differences in mean values were found in most agronomic traits and yield components. Morphological diversity was also observed in the intensity of anthocyanin on the tassels, silks, and brace roots, as well as the leaf edge pattern. Selection can be performed on almost all quantitative traits due to their high broad-sense heritability values. There are three main clusters based on phenotype. Genotypes in cluster 1 such as L15, NEI, M8, M9, L41s, P13, and L42 tended to be potential as hybrids’ parents due to their good per-se morpho-agronomic traits. There is no strong correlation between agronomic traits and yield, but correlations were observed among some traits such as male and female flowering time, plant height and ear height, as well as among other traits.
Keyword: karakterisasi, keragaman genetik, heatmap, characterization, genetic variation

Judul: Evaluation of Agronomic Traits and Yield  Potential of 60 Maize Hybrids (Zea mays L.)
Abstrak: Produksi jagung nasional di Indonesia masih perlu ditingkatkan melalui pengembangan varietas-varietas unggul hibrida untuk memenuhi kebutuhan pangan, pakan, dan industri. Hibrida yang diuji perlu dilakukan evaluasi dan dibandingkan dengan varietas pembanding. Penelitian ini bertujuan mengevaluasi keragaan agronomi dan potensi hasil pada 60 hibrida uji hasil program pemuliaan IPB. Penelitian dilaksanakan pada November 2022 hingga Maret 2023 di Kebun Percobaan Leuwikopo, Bogor. Penelitian ini menggunakan rancangan augmented kelompok lengkap teracak dengan 60 genotipe dan 3 kelompok. Genotipe yang diuji meliputi 6 pembanding, yaitu BISI 18, JHG02, P21, P27, NK Perkasa, dan NK Sumo dengan tiga ulangan, serta 60 hibrida uji tanpa ulangan. Terdapat keragaman genotipe uji jagung pada seluruh peubah pengamatan, kecuali umur berbunga jantan, umur berbunga betina, umur panen, dan jumlah tongkol per tanaman. Semua peubah kuantitatif yang diamati memiliki nilai heritabilitas arti luas yang tinggi, kecuali umur berbunga jantan dan jumlah tongkol per tanaman. Hibrida uji yang potensial adalah H1 x L27, P42 x L23, L15 x L53, L68A x H1, MR14 x B1, P42 x L27, L15 x B4B, B4 x L23, B4 x B1, Nei x P2, P10 x L152, P42 x P10, L15 x Nei, dan L68B x B4B. Produksi hibrida uji tertinggi P42 x L23, National production of maize in Indonesia needs to be increased through the development of superior hybrid maize varieties for food, feed, and industries. The hybrid candidates need to be evaluated and compared with the check varieties. This research aimed to evaluate the agronomic performance and yield potential of 60 maize hybrids from the IPB University breeding program. This research was conducted from November 2022 to March 2023 at the Leuwikopo Experimental Station, Bogor. This study used an augmented randomized complete block design with 60 genotypes and 3 blocks. The genotypes include 6 check varieties, namely BISI 18, JHG02, P21, P27, NK Perkasa, and NK Sumo with three replications, and 60 test hybrids without replication. The genotype effect was significant for all traits observed except for days to tasseling, days to silking, days to harvest, and number of ears per plant. All observed quantitative traits have a high broad-sense heritability estimate except days to taselling and number of ears per plant. The potential hybrid candidates are H1 x L27, P42 x L23, L15 x L53, L68A x H1, MR14 x B1, P42 x L27, L15 x B4B, B4 x L23, B4 x B1, Nei x P2, P10 x L152, P42 x P10, L15 x Nei, dan L68B x B4B. The test hybrid having the highest yield was P42 x L23.
Keyword: evaluation, hybrid, maize breeding, yield

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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