Detection of Garlic Viruses Using SYBR Green Real-time Reverse Transcription-Polymerase Chain Reaction

Abstract

SYBR Green real-time RT-PCR assay was developed and optimized for the sensitive detection of Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV), Garlic common latent virus (GCLV), Shallot latent virus (SLV) and Mite-borne filamentous virus (MbFV). The polyvalence of the designed primers was tested on 50 genotypes of garlic (Allium sativum L.) which originated from different countries. Plasmid standards were prepared and used as positive standards. The efficiencies of all reactions were 97, 93, 99, 98 and 87% for OYDV, LYSV, SLV, GCLV and MbFV standards, respectively. The detection limit for OYDV, LYSV and GCLV was as low as five gene copies, for SLV it was 15 gene copies and for MbFV it was 130 gene copies. In comparison with ELISA, more virus-positive garlic accessions were detected with LYSV and GCLV by SYBR Green-based real-time RT-PCR assay. This method was shown to be a more suitable tool for the detection of highly variable pathogens, such as garlic viruses.