Livestock deaths associated with Clavibacter toxicus/Anguina sp. infection in seedheads of Agrostis avenacea and Polypogon monspeliensis.
Flood plain staggers, a recently discovered poisoning of livestock, has been linked to C. toxicus infection in the seedheads of A. avenacea in northern New South Wales and P. monspeliensis in the southeast of South Australia. Based on colony morphology, serological reactions and bacteriophage specificity, strains of C. toxicus isolated from A. avenacea and P. monspeliensis were indistinguishable from strains from Lolium rigidum, which cause annual ryegrass toxicity. Bacteriophages isolated from C. toxicus on the 3 hosts were indistinguishable from each other based on DNA restriction patterns. In alloenzyme studies, considerable variation was observed between the C. toxicus strains from the 3 hosts, but the variation was within the range exhibited by a single species. Anguina nematodes are associated with C. toxicus infection of A. avenacea and P. monspeliensis. Alloenzyme studies indicated that the same Anguina species probably infects both grasses and that it is not A. funesta, A. agrostis, A. tritici or the species found on velvetgrass (Holcus lanatus). This is the first record of a nematode other than A. funesta as a vector for C. toxicus, and the new vector broadens the range of grasses that the bacterium can infect.