Judul: Genetic Information Mapping of Helicoverpa armigera Nucleopolyhedrovirus DNA Polymerase Gene from Bogor Isolate
Abstrak: Nucleopolyhedrovirus (NPV) merupakan virus entomopatogen dari famili Baculoviridae yang ditemukan menginfeksi berbagai jenis serangga dari ordo Lepidoptera, salah satunya adalah Helicoverpa armigera dari famili Noctuidae. Jenis NPV yang spesifik menginfeksi H. armigera disebut HearNPV. H. armigera merupakan hama penting pada berbagai komoditas seperti jagung, tomat, kapas, dan kedelai. Tujuan penelitian adalah mendesain primer spesifik DNA polymerase dalam teknik PCR yang digunakan untuk melengkapi informasi karakter genetik dari gen DNA polymerase pada HearNPV isolat Bogor. Amplifikasi gen HearNPV dilakukan dengan metode PCR dilanjutkan dengan pengurutan DNA menggunakan program BioEdit dan BLAST. Analisis homologi dan filogeni dilakukan dengan MEGA 11 untuk mengetahui hubungan kekerabatan genetik dari isolat NPV dengan isolat dari negara lain yang terdapat pada GenBank. Hasil amplifikasi PCR menunjukkan ukuran fragmen DNA NPV sebesar 367 pb. Berdasarkan hasil analisis sekuens, isolat HearNPV asal Bogor memiliki hubungan dekat dengan isolat NPV yang berasal dari Spanyol dan India. Nilai homologi nukleotida dan asam amino tertinggi secara berturut-turut sebesar 99,15% dan 99%. Berdasarkan hasil analisis filogeni, isolat HearNPV asal Bogor termasuk dalam kelompok yang sama dengan NPV yang menginfeksi genus Helicoverpa., Nucleopolyhedrovirus (NPV) is an entomopathogenic virus from the Baculoviridae family that infects various types of insects from the order Lepidoptera, one of which is Helicoverpa armigera. HearNPV is an NPV that specifically infects H. armigera. H. armigera is an important pest on commodities such as corn, tomatoes, cotton and soybeans. This study was conducted to design DNA polymerase-specific primers using PCR techniques and to complement the genetic information of the DNA polymerase genes in HearNPV Bogor isolate using those pre-designed primers. HearNPV gene amplification were carried out using the PCR method, followed by DNA sequencing using the BioEdit software and the BLAST program. Homology and phylogeny analyses were carried out using the MEGA 11 program to determine the genetic relationship of NPV isolates with isolates from other countries found in GenBank. The PCR amplification results showed that the size of the NPV DNA fragment was 367 bp. Based on the sequence analysis results, HearNPV isolates from Bogor are closely related to NPV isolates from Spain and India. The highest nucleotide and amino acid homology values were 99.15% and 99%, respectively. Based on the results of phylogenetic analysis, HearNPV isolates from Bogor belong to the same group as the NPVs that infect the genus Helicoverpa.
Keyword: Baculovirus, filogeni, hubungan genetik, sekuens nukleotida, virus serangga

Judul: Molecular Characterization of Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) Bogor Using Polyhedrin Gene
Abstrak: Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) merupakan salah satu hama pertanian yang penting karena dapat mengakibatkan kerugian ekonomi yang tinggi. H. armigera bersifat polifag, multivoltin, dan kosmopolitan dengan kisaran luas inangnya mencapai 300 spesies tanaman, dapat menyerang tanaman jagung, kapas, buncis, dan sorgum. Beberapa gen yang telah digunakan untuk memperoleh informasi genetik dari HearNPV adalah gen late expression factor (lef-8) dan DNA polymerase. Penelitian ini bertujuan untuk mengetahui karakter molekuler NPV pada larva Helicoverpa armigera menggunakan urutan nukleotida polyhedrin serta menganalisis hubungan kekerabatan isolat berdasarkan gen polyhedrin pada HearNPV yang ditemukan di Bogor. Amplifikasi dilakukan menggunakan Polymerase Chain Reaction (PCR). Pengurutan DNA dilakukan dengan menggunakan perangkat lunak BioEdit dan program BLAST. Analisis homologi dan filogenetik dilakukan dengan menggunakan program SDT dan MEGA 11 untuk mengetahui hubungan genetik isolat NPV dengan isolat dari negara lain yang terdapat di GenBank. Hasil amplifikasi PCR menunjukkan bahwa ukuran fragmen DNA NPV adalah 744 bp. Berdasarkan hasil analisis sekuen, isolat HearNPV asal Bogor berkerabat dekat dengan isolat NPV asal Spanyol dan India. Nilai homologi nukleotida dan asam amino tertinggi adalah 99% dan 97%. Berdasarkan hasil analisis filogenetik, HearNPV Bogor termasuk ke dalam kelompok yang sama dengan NPV yang menginfeksi genus Helicoverpa., Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important agricultural pest capable of causing substantial economic losses. This polyphagous, multivoltine, and cosmopolitan species has a wide host range, affecting up to 300 plant species, including corn, cotton, beans, and sorghum. Key genes used to obtain genetic information from HearNPV include the late expression factor (lef-8) and DNA polymerase genes. This study aims to determine the molecular characteristics of NPV in H. armigera larvae using polyhedrin nucleotide sequences and to analyze the phylogeny and homology of isolates based on polyhedrin. Amplification was performed using Polymerase Chain Reaction (PCR), and DNA sequencing was conducted with BioEdit software and the BLAST program. Homology and phylogenetic analyses were carried out using the SDT and MEGA 11 programs to determine the genetic relationship of NPV isolates with those from other countries found in GenBank. The PCR amplification results showed that the size of the NPVs DNA fragment was 744 bp. Sequence analysis revealed that HearNPV isolates from Bogor are closely related to NPV isolates from Spain and India, with the highest nucleotide and amino acid homology values at 99% and 97%, respectively. Phylogenetic analysis indicated that HearNPV Bogor belongs to the same group as NPVs that infect the genus Helicoverpa.
Keyword: filogeni, homologi, HearNPV, Polyhedrin, Polymerase Chain Reaction

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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