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: Molecular Characterization of Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) Using Partial Sequences of DNA Polymerase Gene
Abstrak: Penggunaan agens hayati saat ini semakin berkembang sebagai upaya meminimalkan penggunaan pestisida sintetik. Salah satu contoh organisme yang digunakan dalam pengendalian hayati Helicoverpa armigera adalah Nucleopolyhedrovirus (NPV). NPV termasuk ke dalam Alphabaculovirus yang menjadi salah satu genus pada Baculoviridae. Penelitian ini bertujuan mengetahui karakter molekuler NPV pada larva H. armigera dengan menggunakan sekuens DNA polimerase. Isolat HearNPV diperoleh dari larva H. armigera yang terinfeksi NPV dan telah diperbanyak di Laboratorium Patologi Serangga. Amplifikasi fragmen DNA polimerase HearNPV menggunakan metode PCR dengan sepasang primer forward dan reverse. Selanjutnya, analisis homologi dan filogenetika dilakukan terhadap urutan fragmen DNA polimerase untuk mengetahui hubungan kekerabatannya dengan isolat NPV dari negara lain yang telah terdaftar di GenBank. Hasil analisis homologi nukleotida dan asam amino menunjukkan kekerabatan tertinggi pada nukleotida sebesar 99%, sedangkan pada asam amino sebesar 97%. Berdasarkan hasil analisis filogeni, isolat HearNPV Bogor berada pada kelompok yang sama dengan NPV yang menyerang Genus Helicoverpa asal Australia, Belanda, Brazil, Cina, Jepang, Turki, India, dan Spanyol., The use of biological control is currently growing as an effort to minimize the use of synthetic pesticides. One example of an organism used in the biological control of Helicoervpa armigera is the Nucleopolyhedrovirus (NPV). NPV belongs to the Alphabaculovirus which is a genus in the Baculoviridae. This study aims to determine the molecular characters of NPV in H. armigera larvae using DNA polymerase sequences. HearNPV isolates were obtained from H. armigera larvae infected with NPV and have been propagated in the Insect Pathology Laboratory. Amplification of HearNPV DNA polymerase fragments using the PCR method with a pair of forward and reverse primers. Furthermore, homology and phylogenetic tests were carried out on the DNA polymerase fragment sequence to determine its kinship with NPV isolates from other countries that have been registered in GenBank. The results of nucleotide and amino acid homology analysis showed the highest kinship was at nucleotides at 99%, while at amino acids at 97%. Based on the results of phylogenetic analysis, the Bogor HearNPV isolate was in the same group as the NPVs that attacked the Genus Helicoverpa from Australia, the Netherlands, Brazil, China, Japan, Turkey, India and Spain.
Keyword: Baculoviridae, entomopathogen, homology, nucleotide, phylogeny

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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