Preliminary study on some ornamental plant phytoplasma diseases in north of Iran

Because of the importance of ornamental plants culture in north of Iran, and the outbreak of suspicious symptoms of phytoplasma diseases on these plants, a study was carried out in order to detect and identify phytoplasmas associated with them. The presence of phytoplasma in samples of cockscomb, tagetes and rose plants was shown by direct and nested-PCR assays using the phytoplasma-specific primers, P1/P7 and R16F2n/R2. Sequences of cockscomb, Indian marigold and rose phytoplasmas have high homology with the members of aster yellows phytoplasma group (16SrI). Phylogenetic analysis showed that cockscomb, tagetes and rose phytoplasmas are closely related to 16SrI-M the first one and 16SrI-B the latter two, respectively. To our knowledge, this is the first report of a member of 16SrI group phytoplasma infection in cockscomb in Iran. Moreover, the present study is the first report of phytoplasma disease outbreak on rose in north of Iran by subgroup classification of the associated phytoplasma.