Xanthomonas perforans and X. gardneri associated with bacterial leaf spot on weeds in Brazilian tomato fields

Plants of Nicandra physaloides, Solanum americanum and Euphorbia heterophylla with leaf lesions have been found naturally grown among tomato plants in commercial fields in Brazil. Tomato bacterial spot was occurring in these fields. Xanthomonad-like isolates were obtained from affected weed leaf samples. These isolates were species identified using BOX-PCR and specific primers. Isolates from N. physaloides and S. americanum were identified as Xanthomonas perforans and that of E. heterophylla were identified as X. gardneri. Each of them was able to artificially infect and cause symptoms on the three weed species and tomato plants.