Bacterial ring rot caused by Clavibacter michiganensis subsp. sepedonicus (Cms) is considered as one of the most important bacterial diseases of potatoes and is a constant challenge for potato growers. The disease is distributed in nearly all the countries that grow potatoes and causes high yield losses. Due to its latent stage the bacterium is difficult to detect and spreads quickly.

The symptoms such as plant wilting and tuber rotting characteristic of bacterial ring rot were observed in different localities of Lithuania during 1998–2001. The disease incidence reached on average 5% in the field and 5 to 21% in the storage places. Immunofluorescence staining (IF) and enzymelinked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) were used for Cms detection. Pathogenicity tests were conducted on eggplants.

Keywords: potato, ring rot, Clavibacter michiganensis subsp. sepedonicus