Detection of Japanese yam mosaic virus by RT-LAMP

Arapid and simple procedure is described to detect the genomic RNA molecule of Japanese yam mosaic potyvirus (JYMV). This method, named RT-LAMP, allows direct detection of RNA from infected plants without careful RNA extraction, rapid thermal cycling and gel electrophoresis. RT-LAMP was successfully applied to leaves, propagules and roots of Japanese yam infected with JYMV. One of the characteristics of the RT-LAMP method is its ability to synthesize an extremely large amount of DNA. Accordingly, a large amount of by-product, pyrophospate ion, is produced yielding a white precipitate of magnesium pyrophosphate in the reaction mixture. The presence or absence of this white precipitate allows easy detection of the amplification of JYMV genomic RNA without gel electrophoresis.