Seed transmission of Xanthomonas campestris pvs. graminis and phlei in ryegrass and timothy

In a survey of seed lots of ryegrass (Lolium perenne L. and L. multiflorum L.) and timothy (Phleum pratense L.) collected in Norway, the presence of t he bacterial wilt of forage grass pathogens Xanthomonas campestris pvs. gra minis and phlei, was confirmed by isolation and immunofluorescence staining . By inoculation of seeds, and inoculation of plants for seed production, X . campestris pv. graminis was shown to be seed-transmitted. The level of in fection in seeds was, however, too low to produce plants with disease sympt oms.