Identification of a virus naturally infecting sorghum in India as Sugarcane streak mosaic virus

The virus associated with mosaic disease of sorghum growing around the sugarcane fields in Andhra Pradesh state, India was found to be serologically related to the Sugarcane streak mosaic virus (SStMV) and Sorghum mosaic Parbhani virus (SMPV). The reverse transcription-polymerase chain reaction (RT-PCR) of the total RNA from the enzyme-linked immunosorbent assay positive sorghum samples with the potyvirus specific degenerate primers yielded an amplicon of ∼500 bp. This amplicon sequence had a 95% identity to the SStMV-Andhra Pradesh (SStMV-AP) and SStMV-Coimbatore isolates reported to naturally infect sugarcane in India. Further confirmation was made by RT-PCR of these samples with the SStMV-AP sequence specific primers that yielded ∼1,000 bp amplicon comprising the entire coat protein and 3′ UTR of the viral genome. This amplicon sequence also had a identity of 95% at nucleotide level with the SStMV-AP sugarcane isolate, but at the CP amino acid level it had 97.8% identity. This partial sequence data confirmed the association of SStMV with the mosaic disease of sorghum in Andhra Pradesh state, India. To our knowledge, this is the first report on association of SStMV with mosaic disease of sorghum and designated as SStMV-sorghum isolate.