Association of a ‘Candidatus Phytoplasma solani’-related strain with bindweed witches’ broom in Iran

Plants of Convolvulus arvensis exhibiting symptoms of witches’ broom and little leaves, collectively defined as bindweed witches’ broom, were sampled in pistachio gardens infected by phytoplasmas in Yazd province and assessed for phytoplasma presence by PCR amplification using phytoplasma universal 16S rRNA gene primer pairs. Positive results were obtained and sequence analysis showed that detected phytoplasmas shared 99% identity with sequences related to ‘Candidatus Phytoplasma solani’. Phylogenetic analysis confirmed that bindweed witches’ broom phytoplasma strains represent a close lineage within ‘Ca. P. solani’-related strains. On the basis of disease symptoms and molecular analysis, the bindweed witches’ broom disease in Yazd was associated with the presence of phytoplasmas related to ‘Ca. P. solani’, but differ from the reported strain associated with the scorch disease in pistachio identified in the same fields.