COMPARISON OF REAL-TIME PCR, RT-PCR AND MOLECULAR HYBRIDIZATION TECHNIQUES FOR THE DIAGNOSIS OF GYSVD-1 (GRAPEVINE YELLOW SPECKLE VIROID-1) IN GRAPEVINES

GYSVd-1 is very easily spread mechanically by contaminated cutting tools and infected graft propagation materials and reduces the quality and quantity of grapevines. Rapid diagnosis of viroid infections can be obtained by bioassays, polyacrylamide gel electrophoresis (PAGE), molecular techniques such as polymerase chain reaction (PCR) and hybridization assays. In this study, we aimed to compare three molecular methods including molecular hybridization, real-time PCR and RT-PCR in order to detect GYSVd-1 in grapevines. In the diagnostic analyses conducted with 50 potentially positive grapevine samples, GYSVd-1 was detected in 45 of 50 samples by one or more detection techniques. 18 samples were found to be positive by all methods. 18 other samples gave positive results in real-time PCR and RT-PCR analyses but were negative in molecular hybridization tests. Two samples were positively determined by real-time PCR and molecular hybridization tests. Six grapevine samples were determined only with real-time PCR tests and one sample only with RT-PCR tests. Three molecular methods for detecting GYSVd-1 were compared in this work and we concluded that real-time PCR was the most sensitive amplification method followed by RT-PCR and molecular hybridization. In addition, the realtime PCR method is less time consuming than the other methods.