Detection of strawberry RNA and DNA viruses by RT-PCR using total nucleic acid as a template

Strawberry mild yellow edge virus (SMYEV), Strawberry mottle virus (SMoV) and Strawberry vein banding virus (SVBV), three of strawberry viruses can cause a severe loss in commercial strawberry worldwide. In this paper, total nucleic acid from strawberry leaves was compared with total RNA as the template for detection of the above viruses both by single and multiplex reverse transcription polymerase chain reaction (RT-PCR). Total nucleic acid extract with the modified CTAB method and total RNA extracts with both the modified RNeasy method and the modified CTAB method examined by electrophoresis resulted in a high quality ribosomal 28S and 18S RNA when loaded on an agarose gel. When total RNA and total nucleic acid were used as templates, detection results of SMYEV and SMoV were identical and the amplified band intensity was nearly the same whether by single or duplex RT-PCR. Using total nucleic acid as the template, the detection results of SMYEV and SMoV by multiplex RT-PCR were in a good concord with that amplified by single and duplex RT-PCR, and for SVBV this was similar to the result of detection that amplified by direct PCR using pure DNA as the template. This study demonstrates that total nucleic acid extracted from strawberry leaves by a modified CTAB method is suitable as a template for virus detection by RT-PCR. This makes investigation of the epidemiology of strawberry viruses much easier.