Phytoplasma infection in the four o'clock flower (Mirabilis jalapa)

The four o'clock flower (Mirabilis jalapa L.), a native of tropical South America, has been naturalized as an ornamental garden plant in many parts of the world, including Israel. Plants are multi-branched perennials that produce fragrant colorful flowers over the course of a few months. Plants with small yellow leaves and petite, distorted flowers, resembling phytoplasma-like symptoms, were observed in a home garden in the north of Israel. Using a nested polymerase chain reaction assay (PCR) with phytoplasma universal primers a product of 860 bp was obtained. Sequence analysis of the PCR product associated with infected M. jalapa clustered within a major group of phytoplasmas - 16SrII, peanut witches' broom - and showed a 99% similarity with alfalfa witches' broom, a member of this group. To the best of our knowledge this is the first report of phytoplasma infection in the four o'clock flower.