Determination of Resistance Levels to Clavibacter michiganensis subsp. michiganensis in Some Solanum Species

Clavibacter michiganensis subsp. michiganensis (Cmm), is a devastating bacterial disease agent causing bacterial wilt and canker in tomatoes. There is no definitive solution to prevent yield losses by Cmm in tomatoes. Moreover, there is currently no commercially successful Cmm resistant tomato cultivar on the market. Therefore, we aimed to determine the tolerance level of some tomato accessions to Cmm in the present study. For this purpose, we screened seven tomato accessions representing four species (Solanum arcanum, S. habrochaites, S. pennellii, and S. peruvianum) from Peru, Ecuador, and Mexico against the highly virulent isolates Cmm-244 and Cmm-9. A root immersion method was used to identify new sources of resistance to this important disease. Two accessions, S. habrochaites LA1777, and S. arcanum LA2157 were found to be moderate and highly tolerant, respectively, and could serve as tolerance resources for tomato breeding in Türkiye. These materials can also be investigated more extensively to determine their intrinsic Cmm tolerance mechanism.