Co-Authors:
Spiegel, S., Volcani Center, Bet Dagan, Israel
Rosner, A., Volcani Center, Bet Dagan, Israel
Tam, Y., Volcani Center, Bet Dagan, Israel
Zilkah, S., Volcani Center, Bet Dagan, Israel
Faingersh, E., Volcani Center, Bet Dagan, Israel
Rotbaum, A., Volcani Center, Bet Dagan, Israel
Krizbai, L., Plant Health and Soil Conservation Station, Budapest, Hungary
Abstract:
Prune dwarf ilarvirus (PDV) was identified for the first time in Israel in several imported sweet cherry cultivars and one peach cultivar. Double-antibody sandwich (DAS) and triple antibody sandwich (TAS) ELISA tests were successfully used for PDV detection during spring in most infected cultivars with one exception (cv. Hedelfingen). The sensitivity and reliability of TAS-ELISA was higher than the polyclonal-based assay. ELISA results correlated with graft-inoculation onto Shirofugen indicator plants. Reverse-transcription (RT) and immunocapture (IC) polymerase chain reaction (PCR) amplification assays applied to PDV-infected sweet cherry cultivars yielded consistently a specific product (previously reported by Parakh el al., 1995) except for Hedelfingen. Using diluted sap in IC-PCR resulted in a larger amount of amplified product and improved detection. PCR assays were superior to ELISA, season-independent and generally allowed overcoming the uneven distribution of PDV in woody hosts, typical of ilarviruses. In conclusion, we suggest to include, in addition to biological indexing, a two-step assay for detection of PDV in postentry tests and certification schemes: i) ELISA, preferably a MAB-based assay, especially if large-scale testing is required; and ii) PCR for ELISA-negative and inclusive samples.