Tomato lines from interspecific hybridization donors of resistance to leaf bacterial infections

Daniela Ganeva, Nevena Bogatzevska

Abstract: Leaf bacterial diseases (bacterial spot and speck) infect leaves, stems and fruit of tomatoes and cause both poor yield and fruit grade losses due to defoliation and fruit lesions. Natural populations of causative agents differ in species and race composition. Pseudomonas syringae pv. tomato, races R0 and R1 (bacterial speck) and Xanthomonas vesicatoria (pepper-and-tomato (PT), tomato (T) pathotype, races T1,T2,T3), X. gardneri and X. euvesicatoria (PT,T1,T2,T3) are widely distributed across tomato crops in Bulgaria. Fifteen interspecific hybrid tomato lines derived from crosses with the following wild species from genus Solanum: S. cheesmaniae, S. pimpinellifolium, S. racemigerum, S. chilense and S. hirsutum were studied in this experiment in order to establish their response to diseases. Development of intraspecific hybrid tomato lines (crosses between S. lycopersicum and S. chilense, S. pimpinellifolium or S. racemigerum) is a prerequisite for improving the resistance to X. vesicatoria and X. gardneri. Two lines – L1052 (S. lycopersicum х S. pimpinellifolium) and L1791 (S. lycopersicum х S. racemigerum) were found to be resistant to the races of X. vesicatoria. Performed sequentially individual plant selection in L1787 (S. racemigerum), L1927 and L1921 (S. chilense) reduced the mean disease score and stabilized resistance to the races of X. vesicatoria. The lines L1787 and L1791 were found to be resistant to X. gardneri are S. racemigerum. The wild species S. racemigerum (L1787) was found to have multiple resistance to X. gardneri, the races of X. vesicatoria and P. syringae pv. tomato. This is the first study reporting on the influence of wild species S. racemigerum on the resistance of interspecific hybrid tomato lines towards X. gardneri races of X. vesicatoria and P. syringae pv. tomato.

Keywords: Pseudomonas syringae; resistance; tomato races 0, 1; wild species; Xanthomonas gardneri; Xanthomonas vesicatoria

Date published: 2019-08-27