Judul: Analisis Keragaman dan Korelasi Antar Karakter Biji 204 Aksesi  Padi (Oryza sativa L.) Lokal Indonesia
Abstrak: Bentuk dan ukuran biji padi (Oryza sativa L.) lokal Indonesia menjadi karakteristik agronomis penting, sehingga menjadi target pemuliaan. Penelitian ini mengkaji keragaman 204 koleksi biji padi lokal yang dilanjutkan dengan studi korelasi antar karakter. Data fenotipe dikumpulkan dengan pendekatan citra beresolusi tinggi dan diekstrak menggunakan software SmartGrain, meliputi panjang (L), lebar (W), luas (AS), perimeter (PL), rasio panjang-lebar (LWR), dan sirkularitas (CS). Bulir biji menunjukkan variabilitas sedang hingga tinggi, dengan LWR menjadi karakter paling beragam di antara 204 aksesi yang diteliti. Uji korelasi mengungkapkan karakter PL dan L memiliki koefisien korelasi positif tertinggi, sedangkan karakter LWR dan CS memiliki korelasi negatif tertinggi. Berdasarkan karakter LWR, terdapat tiga tipe bentuk gabah dan beras yaitu biji berukuran sedang adalah yang paling umum dari 204 koleksi biji yang diteliti, sedangkan biji ramping dan agak bulat lebih sedikit. Penelitian ini adalah studi pertama yang melaporkan tentang variasi dan hubungan antar karakter biji padi lokal Indonesia, yang diharapkan dapat berkontribusi dalam menentukan aksesi pilihan terbaik dalam program pemuliaan untuk meningkatkan produktivitas padi., The shape and size of local Indonesian rice (Oryza sativa L.) seeds are important agronomic traits, which can be a target for breeding program. The research examines the diversity of 204 collections of local rice seeds and their correlations. Phenotypic data were collected using a high-resolution image approach and extracted using SmartGrain software, including length (L), width (W), area (AS), perimeter length (PL), length-width ratio (LWR), and circularity (CS). Seed grains exhibited moderate to high variability with LWR being the most diverse character among the 204 accessions. The correlation analysis among seed characters signifies that the characters PL and L show the highest positive correlation, while LWR and CS had the highest negative correlation coefficient. Based on LWR, there are three grain and rice shapes were observed, i.e., slim, medium, dan round-sized seeds, with medium-sized seeds being the most common. This study is the first to report on variations and correlations of local Indonesian rice seed characters, which expect to contribute to selection criteria in breeding programs aimed at increasing rice productivity.
Keyword: fenotiping digital, pemuliaan, SmartGrain, variabilitas

Judul: Character Diversity of Rice Seed Populations RIL Generation F9 Derived from Crossbreeding of Cultivars IR64 and Hawara Bunar
Abstrak: Padi (Oryza sativa L.) adalah tanaman pangan penting bagi penduduk di Indonesia. Meningkatkan produksi padi sangat penting untuk ketahanan pangan nasional. Di antara karakter padi yang dapat mempengaruhi produktivitas padi adalah bentuk dan ukuran biji. Penelitian ini bertujuan untuk menganalisis keragaman dan korelasi karakteristik biji padi populasi recombinant inbred lines (RILs) generasi F9 hasil persilangan kultivar IR64 dan Hawara Bunar. Metode yang dilakukan adalah penanaman padi di sawah, pemindaian biji padi, pengukuran dan pengamatan karakter biji padi. Hasil penelitian menunjukkan bahwa karakter biji dari 256 galur berbeda signifikan antar galur sehingga dapat mengelompokkan galur-galur tersebut menjadi empat kelompok utama. Analisis korelasi antar karakter pada gabah menunjukkan korelasi positif yang sangat nyata antara lebar gabah dengan panjang perimeter gabah dan rasio panjang terhadap lebar gabah. Karakter beras juga menunjukkan korelasi positif yang nyata antara karakter panjang perimeter beras dengan panjang beras dan luas area beras. Karakter biji dapat menjadi karakter pembeda pada 256 galur RIL., Rice (Oryza sativa L.) is an important staple food crop in Indonesia. Increasing rice production is crucial to maintain national food security. Among the rice characteristics that affect productivity are the shape and size of the seeds. The study aimed to analyze the diversity and correlation of seed characteristics in recombinant inbred lines (RILs) population of F9 generation derived from a cross between rice cv. IR64 and Hawara Bunar. Rice plants were cultivated in the paddy field and the seeds were harvested, scanned, observed, and measured the characteristics. The data was statistically analyzed using R software. The results showed that the grain characteristics of the 256 lines were significantly different among the lines and could group the lines into four main groups. Correlation analysis of grain character showed highly significant positive correlations between grain width and grain perimeter length, as well as the length-to-width ratio of the grain. The seed characteristics also exhibit a significant positive correlation between the length of the grain perimeter, seed length, and seed area. The seed characteristics can be used as a marker among the 256 RIL lines.
Keyword: beras, Hawara Bunar, IR64, korelasi, RILs, correlation, 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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