The Presence of Phytoplasma in Black Currant Infected with the Blackcurrant Reversion Disease

A plant of black currant cv. Karlsˇtejnsky´ dlouhohrozen showing symptoms of the severe Russian (R) form of the blackcurrant reversion disease (BCRD) was shown to contain phytoplasma bodies measuring 530–750 nm. Phytoplasma infection was confirmed by polymerase chain reaction (PCR) with the universal primer pair R16F1/R16R0, followed by PCR with the primer pair fU5/rU3. A comparison of the sequence of an amplification product of approximately 880 bp with sequences available in the GenBank confirmed the classification of the phytoplasma in the 16SrI (Aster yellows group). This is the first evidence of the natural occurrence of phytoplasma infection in black currant. Blackcurrant reversion virus (BRV), the cause of BCRD, was confirmed in the plant by RT-PCR. A 481 nt cDNA fragment of BRV was sequenced and compared with sequences in GenBank. Rhabdovirus-like particles were also observed in the plant by electron microscopy