Judul: BREEDING OF HYBRID RICE RESISTANT TO BACTERIAL LEAF BLIGHT AND GOOD GRAIN
Abstrak: Breeding new rice variety does not always give adequate results, therefore it is necessary to develop methods for rice varieties breeding. Hybrid rice is an alternative to increase the productivity of irrigated rice in Indonesia. The new hybrid rice varieties are expected to have high yield potential, resistant to bacterial leaf blight, and have good rice quality. The use of other cytoplasmic CMS types (Gambiaca and Kalinga) aimed to anticipate genetic vulnerability and to increase the diversity of hybrid rice in Indonesia. The objectives of this study were (1) to determine the effect of female parents with different cytoplasmic sources on hybrid seed yield, (2) to select the parental lines of hybrid rice that had good combining ability and heterosis value, (3) to obtain information on the parents and hybrid rice which had BLB resistance and good grain quality, (4) to obtain hybrid rice with high yield, resistant to bacterial leaf blight and good grain quality. The research stages of hybrid rice breeding from three different cytoplasmic sources and had bacterial leaf blight resistant were: (1) Hybrid rice seed production for research materials and to evaluate the ability of seed production for each combination of hybrid rice. This experiment was carried out by crossing CMS parental with restorers to obtain F1 seeds. In the second experiment, there were two activities (2a) combining ability and heterosis value of hybrid rice, (2b) grain and rice quality evaluation. The third experiment was (3) the evaluation of hybrid rice for resistance to bacterial leaf blight. The research was conducted at the Indonesia Center fo Rice Research (ICRR), and in farmer field in Karawang, West Java from March 2021 to March 2022. The first stage is hybrid rice seed production of three cytoplasmic CMS types with 10 restorers to determine F1 seeds production ability which had a good hybrid rice combination. The highest hybrid rice seed yield was obtained from a combination of hybrid rice from female parents GMJ15A, and male parents PK90. The average F1 seed yield of female parental of the Gambiaca type GMJ15A line (1.03 ton ha-1 ) was equivalent to the WA type GMJ12A line (0.85 ton ha-1 ) and was significantly higher than the Kalinga type GMJ14A line (0.51 ton ha-1 ). The male parent (restorer) with the highest average seed yield was PK90 (1.36 ton ha-1 ). The number of grain contents per panicle and the outcrossing rate were positively correlated with the yield of hybrid rice seeds produced. The second experiment was a line x tester to study on the effect of female parents (CMS) and restorers to obtain new hybrid rice combinations with different cytoplasm. The objective of the study was to select the parental lines of hybrid rice that had good combining ability, heterosis and to obtain information on the parents and hybrid rice with high yields. The combined analysis of variance showed a significant effect between locations and hybrid rice on yield components. Results showed that the line parent GMJ14A, testers CRS1301 and CRS1310 had the best general combining ability (GCA). The combination of hybrid rice GMJ12A/R3,
Keyword: bacterial leaf blight resistance, CMS, combaining ability, grain quality and rice quality, heterosis, hybrid rice, restorer

Judul: Performance of Rice Hybrids (Oryza sativa L.) from Crosses of Male Sterile Line and New Plant Type Rice Lines
Abstrak: Padi merupakan salah satu tanaman pangan utama di Indonesia yang berperan penting dalam ketahanan pangan nasional. Peningkatan produktivitas padi melalui pengambangan varietas baru yang adaptif dan berdaya hasil tinggi perlu dilakukan. Sifat agronomi yang baik pada galur padi tipe baru didukung oleh faktor genetik dan lingkungan. Tanaman padi alaminya adalah tanaman menyerbuk sendiri. Oleh karena itu dalam membentuk padi hibrida, penggunaan galur mandul jantan dan galur pemulih kesuburan (restorer) sangat penting. Penelitian dilakukan selama dua musim tanam bulan Mei 2021 hingga Januari 2022 di Kebun Percobaan IPB Sawah Baru dan Laboratorium Mikroteknik Departemen Agronomi dan Hortikultura IPB University, Bogor. Kegiatan dilakukan pada dua musim tanam, yaitu: (1) Pada musim pertama, 15 galur padi tipe baru diuji, serta dilakukan persilangan antara galur mandul jantan sebagai tetua betina dan 15 galur padi tipe baru digunakan sebagai tetua jantan; (2) Pada musim kedua, dilakukan pengujian hibrida yang diperoleh, serta pengujian musim kedua 15 galur tetua padi tipe baru. Kegiatan pengujian 15 galur padi tipe baru selama dua musim dilakukan dengan menggunakan rancangan kelompok lengkap teracak (RKLT) tiga ulangan, serta pengujian hibrida dilakukan dengan RKLT dua ulangan. Hasil penelitian menunjukkan karakter tinggi tanaman, panjang malai, dan umur panen dipengaruhi oleh musim, sedangkan karakter jumlah gabah isi, bobot 1000 butir dan produksi tidak dipengaruhi oleh musim. Genotipe T8 dan T9 memiliki prospek untuk dijadikan galur restorer dalam pembentukan hibrida karena memiliki jumlah gabah isi yang cukup banyak dan didukung dengan karakter- karakter agronomi yang baik. Hal ini juga diperkuat dengan hibrida yang dihasilkan oleh kedua tetua jantan tersebut memiliki bobot gabah per rumpun yang tinggi. Hibrida CMS x IPB189-F-17-3 dan CMS x IPB189-F-132-1-1 memiliki nilai heterosis dan heterobeltiosis dengan nilai positif dan negatif pada masing- masing karakter sesuai dengan tujuan perakitan hibrida. Kedua hibrida tersebut memiliki umur yang relatif genjah dan produktivitas yang relatif tinggi. Hibrida CMS x IPB189-F-17-3 dinilai unggul karena memiliki nilai standar heterosis positif pada karakter bobot gabah per rumpun, jumlah anakan produktif, dan jumlah gabah total., Rice is one of the main food crops in Indonesia that plays an important role in national food security. Increasing rice productivity through the development of new adaptive and high-yielding varieties is necessary. Good agronomic traits in new plant type rice lines are supported by genetic and environmental factors. The rice plant is naturally self-pollinated. Therefore, in establishing hybrid rice, the use of male sterile lines and fertility restorer lines is necessary. The research was conducted during two growing seasons from May 2021 to January 2022 at IPB Sawah Baru Experimental Farm and Microtechnical Laboratory of the Department of Agronomy and Horticulture, IPB University, Bogor. Activities were carried out in two growing seasons, namely: (1) In the first season, 15 new plant type rice lines were tested, as well as crosses between male sterile lines as female parents and 15 new plant type rice lines used as male parents; (2) In the second season, the hybrids obtained were tested, as well as the second season testing of 15 new plant type parents. The testing of 15 new plant type rice lines for two seasons was carried out
Keyword: male parent line, CMS, food resilience, heterobeltiosis, heterosis, productivity, rice hybrid, season, superior varieties

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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