LAUSR

Rose rosette virus (RRV) was characterized as a new member of the virus genus Emaravirus, having a seven single-stranded negative-sense RNA genome. In this communication, partial RdRp gene of RRV has been characterized from infected roses through reverse transcription-PCR using RRV specific primers. The virus was detected in all twenty symptomatic plants tested from the north-eastern region of India and the partial RdRp genes of two isolates were sequenced. Electron microscopy showed the presence of double membrane bodies in all the infected leaf tissues. The three dimensional structure of the RdRp gene of the two isolates was predicted through homology modelling. The partial putative protein of the Siliguri and Siliguri2 isolates of RRV contained a signature motif B (QGNLNMISS) of the Bunyaviridae-RdRp domain. Phylogenetic analysis of these two RRV isolates showed 95–98% sequence identity with other RRV isolates previously described worldwide. After 75 years since the first report, RRV is being reported as an emerging disease of garden roses in India.