European stone fruit yellows phytoplasmas associated with a decline disease of apricot in southern England

Phytoplasmas detected by fluorescence microscopy and polymerase chain reaction (PCR) have been discovered infecting Prunus trees at a site in south-east England. The pathogens were detected in tissue samples taken in autumn and also in spring. The symptoms in infected trees varied from severe decline to absence. PCR experiments using group-specific primers to amplify regions of the 16S RNA gene indicated that the phytoplasmas are similar to European stone fruit yellows isolates occurring in southern and eastern Europe. This is the first record of phytoplasmas in Prunus species in the UK. The origin of the infection is unknown. The implications of this new disease for the fruit industry are discussed.