Bacterial wilt and spot of tomato caused by Xanthomonas vesicatoria and Ralstonia solanacearum in Egypt

Tomato fruits and seed lots were screened for the presence of Xanthomonasvesicatoria and Ralstoniasolanacearum. Yellow colonies of Xanthomonasvesicatoria and white colonies of Ralstoniasolanacearum were consistently isolated on yeast extract-dextrose-calcium carbonate agar medium (YDC) from diseased fruits and seed samples. This was confirmed by isolation on semi-selective medium such as Tween B for Xanthomonas and triphenyltetrazolium salt (TTC) medium for Ralstoniasolanacearum followed by biochemical tests. The four isolates belonging to Xanthomonasvesicatoria and Ralstoniasolanacearum were used to inoculate a local tomato variety. The isolates were found to cause yellowing and wilting of 2-weeks-old seedlings by 8–14 days after inoculation and by 4 weeks all plants had wilted and completely died. Bacteria with the same characteristics as those inoculated were reisolated from the infected plants. Uninoculated plants remained healthy.