Plants of Drummond phlox (Phlox drummondii Hook.) exhibiting symptoms characteristic of viral and phytoplasmal diseases were collected at Vilnius Planting Verdure Trust and at Botanical Gardens of Vilnius and Klaipėda Universities. The causal agents of viral disease, Tobacco mosaic tobamovirus (TMV), was isolated and identified by the methods of test-plants and electron microscopy. The causal agent of phytoplasmal disease was detected in polymerase chain reactions (PCRs) containing phytoplasma universal primer pair R16F2n/R16R2 and template DNA extracted from diseased plants. The 1.2 kbp 16S rDNA product was subjected to single enzyme digestions with 11 different restriction endonucleases. Restriction fragment length polymorphism (RFLP) analysis revealed that the Drummond phlox plants growing in different regions were infected by the same phytoplasma belonging to group 16SrI (aster yellows phytoplasma group), subgroup M.
Keywords: Phlox drumondii, identification, virus, phytoplasma, PCR, RFLP.