Judul: Induksi Umbi Mikro Kentang (Solanum tuberosum L.) secara In Vitro pada Suhu Medium dengan Beberapa Konsentrasi Gula.
Abstrak: The barrier of potato development in Indonesia was the characteristics of potato that specific at low temperature. Therefore, it was important to adaptate potatoes on medium temperature. This research were aimed to study the effect of temperature increasing and sugar concentration on in vitro microtuberization of potato. Potato microtuber of Granola, DTO 28, and CIP 801040 was inducted at low (18–23 0C) and medium temperature (28–31 0C) with three sugar concentrations (90, 105, and 120 g l-1) which used completely randomized design. Medium temperature (28–31 0C) still able to stimulate the formation of microtubers despite the number, fresh weight and tuber dry matter percentage were lower and also had a thick skin and higher phenolic compound. Differences of sugar concentrations did not significantly affect the production of potato microtubers at low temperature and medium temperature. Interaction between increasing of temperature and sugar concentration affected induction of Granola’s buds and the number of CIP 801040’s stolons, roots, and tubers at medium temperature.
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Judul: Optimasi Produksi Bibit Tanaman Kentang (Solanum tuberosum) ‘Granola’ dengan Teknik Fotoautotrofik
Abstrak: Potato is the fourth food in the world after rice, corn, and wheat. Indonesia still imports potatoes for seedlings, seeds and foods, especially for the industry. Indonesian production was law caused farmers have not been producing good quality of potatoes seed, so the demand for seed of potatoes can not filled. The efforts should be made to overcome these obstacles is use biotechnology by micropropagation for potatoes seedling. In vitro plants rarely photosynthesise; their cuticle, vascular tissue between roots and shoots and stomata do not grow and functioning so that the in vitro derived plantlets had low survival in ex vitro conditions. Photoautotrofik system have been developed to overcome the low adaptability of plantlets when acclimatization. This method uses a lower concentration of sugar as an energy source for explants and explants induced to be able to photosynthesise in the semi-open conditions. This condition is more similar to conditions on the ground, so that the explants will have a higher adaptability when the acclimatization. This research aims to study the growth of potato ‘Granola’ cultured in vitro with photoautotrophic system to provide good quality potato explants. This research was conducted at the Laboratory of Tissue Culture 2, morphological analysis of stomata was conducted at the Laboratory of Micro Technique, Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University. The research was conducted from November 2014 until April 2015. This research is consisted of two separate experiments. The first experiment used a single node explant, a second trial using shoot explants. The experiment was arranged in a Randomized Blok Design with two factors concentration of sugar and ventilation. The concentration of sugar are 5, 10, 15, 20 and 25 gL-1, the ventilaion are one and two ventilation. Increases in sucrose concentration correlated positively to the growth of Solanum tuberosum plantlets. Interaction of low sugar and additional ventilation increased the number of stomata and chloroplasts as well as narrowing the diameter of stomata. 45% plantlets grown on media with the treatment of 25 gL-1 sugar with 1 ventilation and 67% on 25 gL-1 sugar with 2 ventilation survived and could be used for seedling production. Interaction of low concentration of sugar with the addition of ventilation in second trial on all treatments significantly increased the density of stomata, number of chloroplast and causes smaller diameter of stomata. In this experiment there is no plantlets were able to survive in the acclimatization stage.
Keyword: potato, in vitro, photoautotrophic, photosynthesis

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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