Sequence analysis of ORF IV RTBV isolated from tungro infected Oryza sativa L. cv Ciherang

The Effort to increase rice production is often constrained by pest and disease such as Tungro. The Tungro disease is caused by the joint infection with two dissimilar viruses; a bacil-form-DNA virus, the Rice tungro bacilliform virus(RTBV) and the spherical RNA virus, Rice tungro spherical virus (RTSV) and transmitted by Green leafhopper (Nephotettix virescens). The symptom of disease is caused by the presence of RTBV. The genome of RTBV consists of four Open reading frames (ORFs) which encode functional proteins. Of the four, ORF IV is unique because it exists only in RTBV. The most efficient method of generating disease resistance plants is to look for natural sources of resistance genes in wild or germplasm and then transfer the gene and the accompanying resistance in cultivated crop varieties. The aim of this study is, therefore, to isolate and analyze of 1170 bp gene of ORF 4 of Tungro virus isolated from an Indonesian rice cultivar, Ciherang (Oryza sativa L. cv Indica). DNA sequencing analysis using BLAST showed 94% similarity with the reference sequence gen bank Acc.M65026.1. The comparisons and mutation analysis of DNA sequences were discussed in this research.