Disease Note.

Characterization of Xanthomonas campestris pv. vesicatoria Strains from Tomato and Pepper Grown in Sudan.. H. Bouzar, University of Florida, 5007 60th St. E. Bradenton 342031; second author, Agricultural Research Cooperation, Gezira Research Station, P. O. Box 126, Wad Medani, Sudan;. N.E. Ahmed, G. C. Somodi, J. B. Jones, and R. E. Stall. First, third, fourth, and fifth authors, University of Florida, 5007 60th St. E. Bradenton 342031; second author, Agricultural Research Cooperation, Gezira Research Station, P. O. Box 126, Wad Medani, Sudan. Plant Dis. Plant Dis. 78:1219. Accepted for publication 21 September 1994.. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1219E.

Leaves and stems of tomato (Lycopersicon esculentum Mill.) and leaves of hot pepper (Capsicum sp.) with suspected bacterial spot lesions were collected from ten locations in central Sudan in 1993. Bacteria were isolated on nutrient agar from lesions and yellow colonies suspected of being Xanthomonas campestris pv. vesicatoria (Doidge) Dye were selected. Twelve strains were characterized serologically, physiologically, and pathogenically as described previously (1,2). ELISA reaction patterns, using a set of six monoclonal antibodies, typed these strains to serovar Al (1). None of the strains hydrolyzed starch or degraded pectate. According to these Phenotypic features, group A strains of X. c. vesicatoria (2) predominate in central Sudan. Differential reactions on tomato and pepper genotypes typed the strains to X. c. vesicatoria race T1P3 (1). All the strains were sensitive to both streptomycin and copper, thus suggesting that copper bactericides should prove useful in controlling the disease. Cajanus cajan L., a plant used to shelter tomato fields in Sudan, often is infected by a bacterial pathogen. None of the bacteria isolated from this plant species were identified as X. c. vesicatoria, thus suggesting that C. cajan is probably not a host of the pathogen causing bacterial spot of tomato and pepper.