Judul: Induksi Pembelahan Sporofitik pada Kultur Antera Kelapa Sawit (Elaeis guineensis Jacq.) dengan Perlakuan Cekaman Suhu dan Media Starvasi.
Abstrak: Haploid culture via androgenesis is a rapid technique to produce pure lines as parental candidates in producing superior hybrid varieties. This technique has not been reported successful in oil palm plant. Cold shock pretreatment followed by combination of starvation medium and temperature treatment, is expected to induce sporophytic division for androgenesis induction in oil palm. The flower buds of oil palm, used in this experiment were derived from the upper part of spikelet located at the middle part of the inflorescence with a half part of spatha was opened. The anthers from this buds contained population of microspores mostly in late uninucleate. Spikelet immersion pretreatment on starvation medium (B medium) in cold temperature (4-9°C) for 1 day then continued by culturing the anthers in double-layer Y3 medium, was able to induce sporophytic division of microspore with 4-5 cells as much as 0.9% after 2 weeks of culture. The percentage of multicellular microspores could be increased up to 2.1%, when after 1 day of pretreatment at cold temperature the anthers were cultured in double-layer B medium at 25-28°C for 7 days, then were subcultured in double-layer Y3 medium at 25-28°C for 1 week after culture. The results of this research could be used as the first step for induction of androgenesis in developing haploid technology in oil palm.
Keyword: oil palm, microspore, sporophytic, pretreatment, starvation

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: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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