Judul: Potensi Penyimpanan Serbuk Sari dalam Produksi Benih Hibrida Mentimun (Cucumis sativus L.) Varietas KE014
Abstrak: High pollen viability with adequate quantity determine yield of hybrid seed production. Stored pollen with high viability is expected to produce high quantity and quality of hybrid seed . The aims of this research was to study the possibility of using stored pollen in hybrid seed production of cucumber (Cucumis sativus L.). The research was conducted in Pollen Laboratory, screen house (SH), and experimental station of PT. East West Seed Indonesia, Gumuk Segawe village, Ajung subdistrict, Jember, East Java from March until August 2011. The research was started with observation on the timing of receptive stigma based on color changes of petal and stigmatic surface every hour during which time pollination was also conducted. Percentage of fruit set and seed set from each pollination were observed. The research then continued with experiments conducted in the field and SH separately. The experiment was arranged in completely randomized block design with 10 treatments in the field and 13 treatments in SH. The treatments for field experiment were combination of storage periode (0, 20, 30 and 40 DAS) and pollination technique (1, 2, 3 times swabbing). The storage periode for SH experiment were 0, 7, 14 and 28 DAS. The treatments were repeated 3 times. The result showed that the stigma was receptive during 07.00–13.00 h. The viability of stored pollen 20-40 DAS ranged between 0.8–4 % whereas 7-28 DAS ranged between 4.8-9.71%. Fruit set from stored pollen ranged 21.23-42.42 % and seed set ranged 16.89-25.26 % in the field compared to use of fresh pollen 54.64 and 59.26 % respectively. As for SH the fruit set ranged 30.69-63.98 % and seed set ranged 18.22–35.68 % from stored pollen compared 73.56 % and 80.69 % from fresh pollen. Reproductive succes of stored pollen in the field ranged 12.82–29.29 % with averaged of 19.89 % compared to that of fresh pollen, whereas in the SH used of stored pollen resulted in 10.60-25.29 %, averaged 18.89 % reproductive succes.
Keyword: stigma receptivity, seed quality, seed set, pollen viability, empty seed

Judul: Cytological Mechanism of Pollen Deterioration and Its Potential in Bitter Gourd (Momordica charantia L.) Seed Production
Abstrak: Pengelolaan serbuk sari memiliki peran penting dalam produksi benih hibrida Cucurbitaceae, dengan tantangan utama pada viabilitas serbuk sari yang menurun dengan cepat. Tujuan dari penelitian ini adalah untuk mendapatkan informasi periode reseptif stigma paria, mempelajari daya simpan dan mekanisme penurunan viabilitas serbuk sari paria selama penyimpanan dan untuk mengetahui potensi serbuk sari paria yang disimpan untuk produksi benih. Penelitian dilaksanakan di Kampus Institut Pertanian Bogor (IPB), Dramaga Bogor, pada bulan September 2018 hingga Juni 2021. Pengamatan ultrastruktur sel dilakukan di laboratorium TEM dan Histologi, Lembaga Eijkman, Jakarta. Periode reseptif stigma diamati secara visual dan berdasarkan fruit set dan seed set dari waktu penyerbukan berbeda (pukul 07.00; 09.00; 11.00; 13.00; dan 15.00). Serbuk sari paria dipanen pada saat bunga mekar kemudian disimpan dalam deep freezer kisaran suhu (-24) hingga (-18) ºC. Pengamatan viabilitas serbuk sari dilakukan pada serbuk sari segar, 0, 2, 4, 6, 8, 10, dan 12 minggu setelah simpan (MSS), sedangkan ultrastruktur serbuk sari pada serbuk sari segar, 4, 8, dan 12 MSS. Serbuk sari yang disimpan juga digunakan untuk penyerbukan di lapangan, kemudian diamati produksi dan mutu benih yang dihasilkan. Hasil penelitian menunjukkan bahwa periode reseptif stigma paria aksesi No 9 (Balitsa) terjadi antara pukul 07.00-11.00. Penyimpanan serbuk sari dalam deep freezer kisaran suhu (-24) hingga (-18) ºC hanya dapat mencegah penurunan viabilitas sampai 4 minggu. Penurunan viabilitas disebabkan oleh degenerasi dinding sel (exine) dan membran mitokondria yang mulai terlihat pada 4 MSS. Exine, membran luar dan dalam mitokondra mengalami degenerasi total pada 12 MSS. Serbuk sari paria yang telah disimpan dalam deep freezer kisaran suhu (-24) hingga (-18) ºC sampai dengan 2 minggu efektif untuk produksi benih bermutu., Pollen management has an essential role in hybrid seed production of Cucurbitaceae, with a significant challenge on the rapid decline of pollen viability. The aims of the research were to obtain information on the bitter gourd stigma receptive period, to study the mechanism of pollen deterioration of bitter gourd during storage, and to investigate if stored pollen is as effective as fresh pollen for seed production. The research was carried out at Dramaga Campus of IPB University from September 2018 to June 2021. Cell ultrastructure observations were carried out at the TEM and Histology Laboratory, Eijkman Institute, Jakarta. The stigma receptive period was observed visually and based on fruit set and seed set from a different pollination time (07.00; 09.00; 11.00; 13.00; and 15.00 h). Bitter gourd pollen was harvested at anthesis and then stored in the deep freezer at a temperature around (-24) to (-18) ºC. Observation on viability was done on fresh pollen, 0, 2, 4, 6, 8, 10, and 12 weeks after storage (WAS), while pollen ultrastructure was on fresh pollen, 4, 8, and 12 WAS. The stored pollen was also used for pollination in the field. Seed production as well as seed quality were observed. The result showed that the stigma receptive period for bitter gourd accession No 9 (Balitsa) occurred between 07.00-11.00 h. Pollen stored in a deep freezer (ranged (-24) to (-18) ºC) would inhibit the declining viability for up to 4 weeks. The declining
Keyword: exine, fruit set, intine, mitokondria, seed set

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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