Resumen de Comparison of enzyme‐linked immunosorbent assays and reverse transcription‐polymerase chain reaction for the reliable detection of Australian grapevine viruses in two climates during three growing seasons

F.E. Constable, J. Connellan, Philip R. Nicholas, B.C. Rodoni

• Background and Aims: Australian certification programs that provide high‐health planting material depend on accurate virus detection methods. The reliability of enzyme‐linked immunosorbent assays (ELISAs) and reverse transcription‐polymerase chain reaction (RT‐PCR) tests for virus detection was compared in Australian conditions.

  Methods and Results: Replicate trials were established in a hot climate and a cool climate with grapevines that were uninoculated or inoculated with Grapevine virus A, Grapevine fleck virus, Grapevine leafroll‐associated virus (GLRaV)‐2 and GLRaV‐3. Grapevines were tested monthly for virus during 3 years. RT‐PCR detected viruses more frequently than ELISA, and the reliability of both tests increased after 12 months and up to 3 years post‐inoculation in both climates.

  Conclusions: Viruses may not be consistently detected until 12 months after an infection event. RT‐PCR is more reliable than ELISA for virus detection during spring and summer. However, detection of viruses was rarely 100% efficient, and retesting of grapevines is recommended to improve the rate of detection.

  Significance of the Study: Validated diagnostic procedures were developed to improve the reliability of grapevine virus detection in Australia.