Differentiation of Poaceae Potyviruses by Reverse Transcription‐Polymerase Chain Reaction and Restriction Analysis

Abstract

Four potyviruses have been reported to infect Poaceae: maize dwarf mosaic virus (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 (one or more) were present. The first step was potyvirus‐group specific and following total RNA extraction, reverse transcription and polymerase chain reaction, it yielded a 327 nucleotide fragment spanning MVWCIEN to QMKAAA conserved motifs in the core of the capside gene. Enzymatic restriction of this fragment with the two endonucleases AluI and DdeI gave virus‐specific patterns. This method was shown to be efficient for dealing with well‐characterized strains and field collected isolates and useful for determining co‐infections and detecting a new potyvirus infecting maize.