In July 2008, a small patch of blackberry (R. fruticosus) growing by the roadside in Egham, England, UK, showed unusual witches' broom symptoms. Proliferations of shoots were observed at the branch nodes, midway along the stem. Symptoms on new growth presented as shortened, narrowed almost leafless branches with reduced, flower production or none at all. Total DNA extracted from plants with symptoms and from healthy-looking blackberry plants was used as a template in a nested PCR assay with universal primers P1m / P7 and fU5 / rU3. Amplicons of expected size (~880 bp) were obtained from plants with symptoms. The phytoplasma 16Sr rDNA sequence (GenBank accession no. FJ008925) was compared with those held in the GenBank using BLAST. The greatest similarity (99%) was with phytoplasmas of group 16SrI, 'Candidatus Phytoplasma asteris' [Phytoplasma asteris], including those associated with gaillardia yellows (EF583066), poa stunt (DQ640502), and festuca yellows (DQ640504). This is the first record of a phytoplasma from 16SrI group recorded from Rubus in the UK.
Reeder, R.; Kelly, P.L.; Arocha, Y. &#8216;Candidatus Phytoplasma asteris&#8217; identified in blackberry (Rubus fruticosus agg.) in the United Kingdom. Plant Pathology (2010) 59 (2) 394-394. [DOI: 10.1111/j.1365-3059.2009.02195.x]