An appraisal of different methods for the detection of the walnut strain of cherry leafroll virus.

Three methods were evaluated for the detection of cherry leafroll virus: ELISA, dot-blot and reverse transcriptional polymerase chain reaction (RT-PCR). Dot-blot and RT-PCR were carried out in crude plant extracts without any further RNA purification. Dot-blot hybridization using a 32P-labelled DNA probe was as sensitive as previously reported ELISA results for cherry leafroll virus detection. The most sensitive method was RT-PCR, which amplified a specific fragment of 448 bp from the 3' untranslated region of both viral genomic RNAs. RT-PCR was used to detect cherry leafroll virus in infected walnut buds and twigs.