Judul: Deteksi Virus yang Menginfeksi Kentang (Solanum tuberosum L.) di Jawa Barat
Abstrak: Symptoms of viral infection were found in the center of potato cultivations in West Java (Rancabali, Pengalengan, and Bayongbong). However the viruses associated with these symptoms had been unknown yet. The conducted research aims to detect and identify the viruses molecularly. Fifty leaf samples were randomly collected from symptomatic potato plants of 50 samples at each location. Paramaters measured were symptoms, disease incidence, and viral DNA sequences which were predominantly found. Disease incidence was determined by serological tests using PVY, PVX, PVS, and CMV antiserum. While nucleic acid was amplified by RT-PCR and DNA sequencing. The result showed that the symptoms were found vary in potato leaves, such as mosaic, vein clearing, vein banding, rugose, and leaf malformation. Disease incidence of PVY, PVX, PVS, and CMV in Rancabali were 28%, 0%, 0%, and 28%, in Pengalengan were 80%, 24%, 2%, and 82%, and in Bayongbong were 82%, 0%, 6%, and 74%, respectively. RT-PCR using specific DNA primers successfully amplify PVY and CMV coat protein gene from Bayongbong each approximately size 801 bp and 657 bp. The homology of nucleotide and amino acid of PVY from Bayongbong against PVY isolates from the other countries ranged from 89.5-99.7% and 92.0-100%. The highest homology was closely to PVYNTN from China and Japan. Whereas the homology of nucleotide and amino acid of CMV from Bayongbong against CMV isolates from the other countries ranged from 87.6-96.9% and 86.9-93.7%. The highest homology was closely to CMV strain Soybean stunt (SS) from Bogor (Indonesia). Both of viruses strain (PVYNTN and CMVSS) and PVS were the first reported in potato crops in Indonesia.
Keyword: PVY., potato, CMV

Judul: Deteksi Geminivirus yang menginfeksi tanaman terung (Solanum melongena L.) dengan teknik Polymerase Chain Reaction.
Abstrak: Diseases caused by whitefly-transmitted Geminiviruses (WTGs) have become serious constraints for crops throughout the world, including Indonesia. WTGs has been reported to cause significant yield loss especially in chili pepper and tomato in Java. This research aims to detect and identify Geminivirus infecting eggplant using polymerase chain reaction (PCR) and nucleotide sequencing. The methods involved DNA extraction using CTAB, DNA amplification and nucleotide sequence analysis by Bioedit V 7.0.5 and ClustalW. Three pair of universal primers, i.e. pAL1v1978/pAR1c715, SPG1/SPG2, pAV494/pAC1048, was used for DNA amplification. Infection of Geminivirus was evidenced from leaves collected from West Java (Bandung) and Central Java (Pati, Rembang, Bantul). Universal primer SPG1/SPG2 was able to amplify DNA fragments of ≈912 bp from all leaf samples. Nucleotide analyses showed that Geminivirus infecting eggplant from West Java and Central Java has a close relationship (98.8%) with Tomato yellow leaf curl Kanchanaburi virus (TYLCVKaV) from Thailand.
Keyword: universal primers., sequence analysis, DNA amplification

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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