Detection and identification of seed-borne pathogenic bacteria of imported tomato seeds in Egypt

Imported tomato seed lots of different cultivars were assayed for the presence of seed-borne bacterial pathogens. The liquid assay method was used for detection of the bacteria, and seed extracts were plated on different semi-selective media. Pseudomonas corrugata and Xanthomonas campestris pv. vesicatoria were detected in 14.7% and 12% of the seed samples tested respectively. These pathogens were identified by means of biochemical, physiological and pathogenicity tests as well as the Biolog GN Microplate System for X. campestris pv. vesicatoria. Both P. corrugata and X. campestris pv. vesicatoria were more easily identified on Tween B and CKTM media than on other media. This is the first report of the occurrence of these important pathogens on tomato seeds in Egypt.