Characterization of the coat protein gene of Cymbidium mosaic virus isolates from India

The variability in the coat protein (CP) gene sequence of Cymbidium mosaic virus (CymMV) that naturally infects orchids worldwide was investigated. Samples were collected from different regions of India, and the gene encoding the CP of nine isolates was specifically amplified by reverse-transcription polymerase chain reaction. The amplified product obtained was cloned, sequenced and multiple sequence alignment of deduced amino acid (aa) sequences revealed considerable homology to CymMV isolates from other countries. The nucleotide sequences and the amino acid sequences were found to be 85-100% identical and 65-100% respectively. Such high sequence conservation suggests that the CymMV CP gene is highly conserved and is a suitable candidate for the development of diagnostic procedures and to provide transgenic resistance to orchids cultivated in different geographical locations. Although recombination is not common among CymMV isolates, one isolate from Cymbidium was found to be a recombinant between a Korean and a Thai isolate of the virus. IHBT communication no: 0451.