Judul: Induksi Keragaman Genetik Dengan Mutagen Sinar Gamma pada Nenas Secara In Vitro
Abstrak: Nenas (Ananas comosus (L.) Merr) merupakan tanaman buah yang potensial untuk dikembangkan karena telah banyak digunakan baik sebagai makanan segar, bahan industri makanan, kosmetik, obat-obatan dan industri tekstil. Produktivitas nenas di Indonesia masih rendah dan rasio bobot buah dengan tanaman hanya berkisar 0.43-0.46, sedangkan di negara maju telah mencapai rasio 0.6. Pusat Kajian Buah Tropika IPB telah memiliki klon harapan nenas yang memiliki kualitas buah unggul, namun produktivitasnya masih rendah. Salah satu kendala dalam meningkatkan produktivitas di lapangan secara agronomi adalah diameter tajuk yang lebar mecapai 1 m, daun yang panjang mencapai 1 m atau lebih, serta kedudukan daun terkulai sehingga memerlukan jarak tanam yang lebar.
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Judul: Induksi Keragaman Genetik dengan Mutagen Sinar Gamma pada Nenas Secara In Vitro
Abstrak: Improvement of the genetic variability of pineapple plant can be done by mutation induction with gamma rays. The aim of the research was to increase genetic variability on pineapple through gamma irradiation of calli that have been frequently subculture. Medium for calli induction was MS + 1 mg L-1 benzylaminopurine (BAP) + 0.05 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D), while the medium for shoot regeneration was MS + 1.5 mg L-1 kinetin + 0.5 mg L-1 NAA. Calli were then irradiated with 0, 15, 25 and 35 Gy gamma irradiation. Completely randomized design with 40 replication were used in this experiment. The result showed that irradiation gamma rays were affected on growth and regeneration on calli. Generally, the 15 Gy induced variance of shoot growth, phenotypic and genetic variability. Gamma irradiation changed the banding pattern of DNAs as they were amplified with five primers of ISSR molecular marker to analysis genetic variability among regenerant. Serial selection based on erect leaves structures and narrow canopy diameter character resulted to seven regenerants mutant with erect leaves structure and narrow canopy diameter without reducing plant height and leaves number compared to those of control regenerants population.
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Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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