Identifikasi Molekuler Spodoptera litura Nucleopolyhedrovirus (SpltNPV) Isolat Bogor Berdasarkan Gen Per Os Infectivity Factors-2.

Abstract

Spodoptera litura nucleopolyhedrovirus (SpltNPV) merupakan agens hayati yang telah berhasil dikembangkan sebagai bioinsektisida untuk mengendalikan ulat grayak S. litura. SpltNPV memiliki gen penting dalam proses masuknya virus ke dalam sel epitel usus yang disebut gen per os infectivity factor (pif). Identifikasi molekuler dan karakterisasi mengenai pif-2 dilakukan agar dapat melengkapi susunan lengkap gen SpltNPV isolat Bogor. Penelitian ini bertujuan mengidentifikasi secara molekuler dan mengetahui kekerabatan SpltNPV yang menyerang S. litura di Bogor berdasarkan gen pif-2. Amplifikasi gen pif-2 SpltNPV dilakukan menggunakan metode Polymerase Chain Reaction (PCR) dengan menggunakan primer spesifik hasil rancangan peneliti. Target amplikon adalah ±1300 pb (pasang basa) dengan primer pif-2 F1 forward (5’- CCAGCATGAACACGATTAG -3’) dan primer pif-2 R1 reverse (5’- GGTATTTGAATTTGGCCATTG-3’). Gen pif-2 SpltNPV isolat Bogor hasil amplifikasi memiliki panjang ±1230 pb. Hasil analisis homologi sekuens Gen pif-2 memiliki kekerabatan tertinggi dengan isolat SpltNPV asal China sebesar 99,2% dan isolat SpltNPV strain B-0-4 asal Jepang sebesar 98,9%. Namun, asal-usul evolusi belum dapat dipastikan karena data pembanding masih didominasi isolat dari China sehingga diperlukan analisis lebih lanjut.

Spodoptera litura nucleopolyhedrovirus (SpltNPV) is a biological control agent that has been successfully developed as a bioinsecticide to control the armyworm S. litura. SpltNPV possesses several essential genes known as per os infectivity factors (pif), which are crucial for the virus to enter the epithelial cells of the host's midgut. Molecular identification and characterization of pif-2 were conducted to complement the complete genomic profile of the Bogor isolate of SpltNPV. This research was designed to molecularly identify and determine the phylogenetic relationship of SpltNPV that infects S. litura in Bogor based on the pif-2 gene. Amplification of the pif-2 gene of SpltNPV was performed using the Polymerase Chain Reaction (PCR) method with researcher-designed specific primers. The target amplicon was approximately 1300 base pairs (bp), using the forward primer pif-2 F1 (5’-CCAGCATGAACACGATTAG-3’) and the reverse primer pif-2 R1 (5’-GGTATTTGAATTTGGCCATTG-3’). The amplified pif-2 gene of the SpltNPV Bogor isolate had a length of approximately 1,230 base pairs (bp). Homology analysis of the pif-2 gene sequence from the Bogor isolate showed the highest similarity with the SpltNPV isolate from China at 99.2%, and with the SpltNPV strain B-0-4 from Japan at 98.9%. However, the evolutionary origin of the virus cannot yet be determined with certainty, as the available comparative data are still dominated by isolates from China. Therefore, further analyses involving isolates from other regions are required.