Stolbur phytoplasmas infecting chrysanthemum plants in Serbia.

During a survey on ornamental crops growing in open field, chrysanthemum plants showing flower proliferation, virescence and stunting were observed. To verify possible phytoplasma association with described symptoms, polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analyses on phytoplasma 16Sr DNA were carried out. Phytoplasmas belonging to 16SrXII-A ribosomal subgroup (stolbur) were identified in all samples tested from symptomatic plants. This first report of 16SrXII-A stolbur phytoplasmas in chrysanthemum with flower proliferation and stunting symptoms allow to distinguish this from already known chrysanthemum yellows associated with phytoplasmas belonging to aster yellows 16SrI-B ribosomal group, ’Candidatus Phytoplasma asteris’.