Multigene characterization of phytoplasmas infecting jujube and paulownia in China.

Molecular characterization of phytoplasmas in original and micropropagated jujube and paulownia samples collected from plants showing witches’ broom symptoms was carried out. Ribosomal (16S rRNA) and non-ribosomal genes of the phytoplasma associated with the two diseases were studied after amplification by nested-PCR, using restriction fragment length polymorphism analyses with informative endonucleases. The phytoplasmas infecting paulownia were identified as belonging to ribosomal subgroup 16SrI-D, while those infecting jujube belonged to 16SrV-B. Further molecular characterization show little variability in the other studied genes of these phytoplasmas between original and micropropagated plant material, indicating stability of the population of pathogenic strains of these two phytoplasma when derived from the same original plant.