Judul: Perkembangan Mikrospora dan Induksi Pembelahan Sporofitik pada Kultur Antera Kelapa Sawit (Elaeis guineensis Jacq.)
Abstrak: Pengembangan varietas hibrida kelapa sawit membutuhkan ketersediaan galur-galur murni untuk dijadikan tetua. Teknologi haploid dapat dikembangkan untuk menghasilkan galur-galur murni (tanaman haploid ganda) secara efisien hanya dalam 1-2 generasi. Penelitian ini bertujuan menginduksi pembelahan sporofitik pada kultur antera dalam media dua lapis yang merupakan langkah awal pengembangan kultur haploid pada kelapa sawit. Pangkal spikelet dari spikelet yang terdapat pada pangkal malai dari malai jantan yang memiliki ¼ bagian pangkal malai berwarna kuning dan ¾ bagian ujung malai berwarna coklat mengandung mikrospora tahap uninukleat akhir. Sedangkan ujung spikelet dari spikelet yang terdapat pada ujung malai dari malai jantan berwarna coklat dan sebagian seludang telah terbuka mengandung mikrospora tahap biselular awal. Mikrospora tahap uninukleat akhir yang dikulturkan pada media standar embriogenesis somatik kelapa sawit, memperlihatkan perkembangan gametofitik sampai tahap biselular pada umur 6 sampai 10 hari setelah kultur (HSK). Pemberian cekaman suhu tinggi (32-33ºC) dalam periode 0, 1, 3 dan 7 hari yang dikombinasikan dengan perlakuan sumber karbon berupa sukrosa, maltosa ataupun manitol tidak dapat menginduksi pembelahan sporofitik dalam antera pada kutur in vitro. Namun perlakuan cekaman suhu tinggi selama satu hari yang dikombinasikan dengan sumber karbon maltosa 40 g/l dapat mempertahankan persentase mikrospora hidup sebesar 74.5% sampai 28 HSK.
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Judul: Viabilitas dan Perkembangan Mikrospora dalam Kultur Antera Kelapa Sawit (Elaeis guineensis Jacq.) dengan Perlakuan Suhu Rendah dan Konsentrasi Maltosa
Abstrak: Haploid technology through anther culture is an alternative means to accelerate genetic stability of crops. Development and application of this technology in oil palm (Elaeis guineensis Jacq.) will enhance the establishment of haploid and double haploid plants in only one generation. The objective of this study was to determine the effect of low temperature stress and carbon source of maltose concentration on the viability and development of microspore to induce sporophytic division in anther culture of oil palm in a double layer medium system. The treatment was a combination of incubation period of cold stress (4-9°C) and concentration of maltose as carbon source. Anthers used containing microspores mostly at late uninucleate phase (30-41%) and early binucleate (42-59%) were obtained from male flowers from half open spatha at middle spikelet position. Microspores cultured in all concentrations of maltose and low temperature stress in general continued to grow gametophyitically then gradually die. However, the viability of microspores on the medium with carbon source 20 g/l maltose and incubation period of low temperature stress for one day was approximately 52% at 5 weeks after culture. From this treatment, there was indications that the induction has been initiated shown by the finding of sporophytic division of microspores with two relatively symmetrical nuclei, although in a very low percentage.
Keyword: maltose, microspore, temperature, palm oil, Sporophytic division

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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