Differentiation of poaceae potyviruses by reverse transcription-polymerasechain reaction and restriction analysis

Four potyviruses have been reported to infect Poaceae: maize dwarf mosaic v irus (MDMV), sugarcane mosaic virus (SCMV), johnsongrass mosaic virus (JGMV ) and sorghum mosaic virus (SrMV). A procedure was developed to assess the potential presence of potyviruses in a Poaceae-infected sample, and then to determine which potyvirus species tone or more) were present. The first st ep was potyvirus-group specific and following total RNA extraction, reverse transcription and polymerase chain reaction, it yielded a 327 nucleotide f ragment spanning MVWCIEN to QMKAAA conserved motifs in the core of the caps ide gene. Enzymatic restriction of this fragment with the two endonucleases AluI and DdeI gave virus-specific patterns. This method was shown to be ef ficient for dealing with well-characterized strains and field collected iso lates and useful for determining coinfections and detecting a new potyvirus infecting maize.