Susceptibility of Anguina Funesta (Nematoda: Anguinidae) Populations To Adhesion By the Toxigenic Clavibacter Sp. Responsible for Annual Ryegrass Toxicity

Abstract

Three hundred and twenty populations of Anguina funesta from ryegrass (Lolium rigidum) pastures of South Australian and Western Australian wheat belts were examined for their susceptibility to adhesion of a single strain of the toxigenic bacterium Clavibacter sp., responsible for annual ryegrass toxicity. The frequency distribution of nematodes receptive to adhesion by the bacterium differed between the States and between regions within South Australia. The more recently infested areas appeared to have a higher frequency of nematodes susceptible to adhesion. The pattern observed in South Australia indicated that adhesion in this bacterial strain to the nematode may be determined by a single recessive gene, which would have implications for management. The concentration of bacterially colonized galls and the occurrence of toxicity appeared to be reduced when numbers of nematodes susceptible to adhesion were low.