Judul: Induction of somaclone variation through gamma irradiation and in vitro selection to obtain drought tolerance patchouly
Abstrak: Tanaman nilam (Pogostemom cab/in Benth.) merupakan salah satu tanaman penghasil minyak atsiri yang dikenal dengan minyak nilam (patchouly oil). Indonesia merupakan negara pemasok terbesar kebutuhan minyak nilam dunia, yang mencapai sekitar 90 % dari seluruh kebutuhan dunia. Tanaman nilam umumnya dibudidayakan pada lahan kering, sehingga salah satu resiko pengembangannya adalah masalah kekeringan. Sempitnya keragaman genetik dan terbatasnya jumlah klon yang tersedia merupakan salah satu kendala dalam melakukan seleksi untuk memperoleh klon unggul yang adaptif terhadap cekaman kekeringan. Penggunaan iradiasi sinar gamma pada kalus nilam yang telah mengalami subkultur berulang merupakan upaya yang dilakukan untuk meningkatkan variasi somaklonal, dan melalui seleksi in vitro menggunakan agen penyeleksi Polyethilene Glycol (PEG), diharapkan diperoleh tanaman nilam yang toleran terhadap cekaman kekeringan sebagaimana tujuan clari penelitian ini. Penelitian dilaksanakan di Lab.Biologi Sel dan Jaringan Pusat Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian Bogor. Iradiasi sinar gamma dilaksanakan di Pusat Aplikasi Teknologi Isotop dan Radiasi (PATIR) Badan tenaga Atom Nasional (BATAN) Jakarta. Penelitian berlangsung dari Juli 2004 s/d Januari 2007. Bahan tanaman yang digunakan adalah klon nilam Tapak Tuan (TT75) basil perbanyakan secara in vitro dan merupakan salah satu klon harapan yang dikoleksi Balitbiagen., Patchouly (Pogostemon cab/in Benth.) is a source of patchouly oil. Indonesia is the biggest producer of patchouly oil in the world, reach to 90 % supply. Generally, patchouly is cultivated at dry land so that drought stress becomes the one of problem for this development. Low level of genetic diversity and limitation of clones are also the other problem to get superior clone that adaptive to drought stress. The use of gamma irradiation of fragment sub culture calli is the one alternative way to increase somaclonal variation and via in vitro selection using PEG as the selective agent is expected to obtain drought tolerance patchouly. The research was conducted at the Tissue Culture Laboratory of Research Center of Biotechnology and Genetic Resources, Bogor. Gamma irradiation treatment was done at the Center for Application of Isotope and Radiation •Technology-BAT AN, Jakarta from July 2004 to January 2007. Plant material was Tapak Tuan clone obtain from in vitro proliferation and the one of the most expection candidate clone that Balitbiogen collected.
Keyword: Calli, Somaclonal variation, Gamma inadiation, Pohjelilene glycol

Judul: Morphological Characterization of Patchouli (Pogostemon cablin Benth.) Clones Irradiated by Gamma Ray
Abstrak: Patchouli plant (Pogostemon cablin Benth.) is one of the plants that produce patchouli oil which is one of Indonesia's leading export commodity. However, patchouli breeding has limitations because patchouli cultivated in Indonesia is non-flowering plant, thus it difficult to develop superior varieties due to the low genetic variability. Induction of physical mutations by gamma-ray irradiation can increase genetic variability. This study aims to determine the variation of morphological characters from gamma-ray irradiation of Aceh patchouli. This study used a Randomized Complete Block Design (RCBD) with 1 factor, three doses of gamma irradiation divided 0, 20 + 40 Gy, 60 + 80 Gy, and control patchouli planted in the field. The results of the study observed that increasing the dose of gamma-ray irradiation inhibit plant growth. Plant control A1 (0 Gy) showed the best growth parameters such as internode length, plant height, leaf length, leaf width, stem diameter, number of branches, and amount of chlorophyll, fresh weight and dry weight. Irradiation plant A2 (20 + 40 Gy) resulted diversity phenotype in such as the character of leaf tip shape, stem color, and branch surface texture., Tanaman nilam (Pogostemon cablin Benth.) menjadi salah satu tanaman yang menghasilkan minyak nilam sebagai komoditi unggulan ekspor Indonesia. Pengembangan tanaman nilam memiliki keterbatasan karena tanaman nilam yang dibudidayakan memiliki sifat tidak dapat berbunga, sehingga keragaman genetiknya rendah. Induksi mutasi fisik dengan iradiasi sinar gamma dapat meningkatkan keragaman genetik menghasilkan variasi fenotipe yang berbeda. Penelitian ini bertujuan mengetahui keragaman morfologi tanaman nilam hasil perlakuan iradiasi sinar gamma. Penelitian ini menggunakan rancangan acak kelompok lengkap teracak (RKLT) dengan 1 faktor yaitu pengaruh perbedaan dosis radiasi sinar gamma dengan interval 0, 20 + 40 Gy, 60 + 80 Gy, dan tanaman nilam nilam asal sebagai kontrol. Hasil penelitian menunjukkan bahwa peningkatan dosis radiasi sinar gamma yang dapat menghambat pertumbuhan tanaman. Perlakuan dosis iradiasi 0 Gy (A1) menunjukkan kualitas pertumbuhan terbaik seperti parameter panjang ruas, tinggi tanaman, panjang daun, lebar daun, diameter batang, jumlah cabang, jumlah klorofil, bobot basah dan bobot kering. Sedangkan perlakuan dosis iradiasi 20 + 40 Gy (A2) menghasilkan pertumbuhan keragaman fenotipe terbanyak pada tanaman nilam seperti pada karakter bentuk ujung daun, warna batang, dan tekstur permukaan cabang.
Keyword: Aceh patchouli, gamma-ray irradiation, genetic variation, mutation

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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