Resistance responses of plants regenerated from tomato anther and somatic tissue cultures to Clavibacter michiganense subsp michiganense

The production of gametoclonal and somaclonal variants in tomato is of great importance for the genetic improvement of tomato hybrids and cultivars. The possibility to obtain tomato plants resistant to Clavibacter michiganense subsp. michiganense (Cmm) through anther and tissue culture was investigated in the present study. Regenerants from anther and tissue cultures and their progenies (R-1-R-3) in the cultivars Roma ins and Bella, lines L. 24-13, and L. 6944, as well as the hybrids Roma ms x UC 82A, Roma ms x L. 31, Roma ms x Bella, and Cristy, were tested for resistance to Cmm. The regenerants differed in their resistance to Cmm. All regenerants from the anther culture of the genotype Roma ms and Roma ms x UC 82A are susceptible to the disease, while those from Bella and Roma Ins x L. 31 vary from susceptible to resistant. The highest number of regenerants obtained from somatic tissue culture lacking disease symptoms until the end of the vegetation was observed in the genotypes Cristy and L. 24-13. Variation in regenerant resistance is found in R-1, R-2, and R-3. The results suggest that the gametoclonal and somaclonal variation may be efficiently applied to obtain tomato plants resistant to Cmm.