Infection of oats and other cereals by oat chlorotic stunt virus in the field and laboratory

During 1992/1993 and 1994/1995, field experiments were carried out to investigate the infection of several cultivars of oats, other cereals and grasses, with oat chlorotic stunt virus (OCSV), which is provisionally identified as a member of the Tombusviridae . Under field conditions a high percentage of oat plants became infected when sown in infested soil and there was little difference in susceptibility between the oat cultivars compared. Although plants of other Poaceae such as winter wheat, winter barley and annual meadow grass also became infected, the percentage was low and the virus titre reached was much lower than in oats. In most infected plants the virus was localized within the roots, and only in a few plants did it spread systemically. This suggests that the virus was acquired through the roots, indicating further similarities between OCSV and members of the Tombusviridae . Several cereals, including oats, wheat, barley and maize, were infected by mechanical inoculation using an embryo-wounding technique; in the majority of cases virus infection only reached a low titre.