Use of ELISA for detection of Clavibacter michiganensis subsp. michiganensis in tomato 1

A DAS‐ELISA method has been developed to detect the causal agent of bacterial canker of tomato, Clavibacter michiganensis subsp. michiganensis. The high sensitivity of the test can be attributed to antibodies which are produced against soluble antigens (extracellular products). The most suitable part of the tomato plant for reliable detection of the bacterium is the lower stem region. It is possible to differentiate heavy and weak symptom expressions by ELISA. The ELISA procedure also allows detection of C.m. michiganensis in symptomless tomato plants. Furthermore, the bacterium has been detected in tomato seeds harvested from infected plants.