Judul: Pengaruh iradiasi sinar gamma pada polen kelapa Genjah Salak
Abstrak: Coconut plants are classified into two types namely Tall coconut and Dwarf coconut. Salak Dwarf coconut derived from South Kalimantan, the characteristic of Salak Dwarf Coconut is that is grow faster than Tall coconut. The objective of this research is to analyze the effect of gamma irradiation on pollen viability and chromosomes of Salak Dwarf coconut pollen. Pollen viability and chromosome pollen of Salak Dwarf coconut pollen were observed using microscope. The higher dosage of gamma irradiation, the lower pollen germination. At lethal doses of (LD50) gamma irradiation had caused the pollen germination viability less than half, from 31% to 14 to 19%, were 5-10 Gy. The dosage level of gamma irradiation dosages 5-15 Gy Chromosome number increase, how ever at dosage level 20-30 Gy chromosome number decrease. Irradiation caused the chromosome changed. Chromosomes number differed the level of gamma irradiation dosages. Artificial pollination in coconuts using gamma irradiation pollens should be used dosage irradiation less than 5 Gy.
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Judul: Pengaruh iradiasi sinar gamma terhadap pertumbuhan plb anggrek Dendrobium lasianthera (JJ. Smith) secara in vitro
Abstrak: This research aimed to learn the effect of gamma ray-irradiation on protocorm like bodies (plb) Dendrobium lasianthera and determined Lethal dosage (LD) 30 and 50. The irradiation has done at the Center of Technology Application of Isotops and Radiation, Nuclear Energy Agency (PATIR-BATAN), the research started from February 2014 to July 2014. The research implemented the completely randomized design (CRD) with a single factor that gamma rayirradiation dosage were 0 Gy, 20 Gy, 40 Gy, 60 Gy, 80 Gy, and 100 Gy. Each dose of gamma ray-irradiation treatment was repeated 5 times, of which there were 30 units of the experiment and each experimental unit consisted of five culture bottles were individually planted 4 plb Dendrobium lasianthera. The results of this research showed that the effect of gamma ray-irradiation dose significantly decreased the percentage of live plb, percentage of plb germination, number of leaves, number of roots, the percentage of rooted plant. Plantlets changes observed among other wide leaves, and the spiral leaves. Lethal dose 30% (LD30) was at 19.7697 Gy irradiation dose and LD50 was at 67.3504 Gy irradiation dose.
Keyword: Bogor Agricultural University (IPB), mutation, Lethal Dosage (LD), in vitro, gamma ray-irradiation, Dendrobium lasianthera

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology