Specificity of the Adhesion of Some Plant Pathogenic Micro-Organisms To the Cuticle of Nematodes in the Genus Anguina (Nematoda: Anguinidae)

Abstract

The adhesion of Dilophospora alopecuri conidia from two host species and 35 strains of plant pathogenic corynebacteria to seven populations of seed-gall nematodes, Anguina spp., was investigated. The nematodes included Anguina agrostis from Agrostis capillaris, Anguina funesta from Lolium rigidum, Anguina tritici from Triticum aestivum, Anguina sp. from Stipa scabra ssp. falcata and Anguina sp. from Holcus lanatus. Only corynebacteria that cause gummosis diseases of grasses (Clavibacter iranicum, Clavibacter rathayi, Clavibacter tritici, Clavibacter sp. associated with annual ryegrass toxicity and ''Corynebacterium agropyri'') and mostly known to be associated with an Anguina vector adhered to the nematodes. Adhesion was not restricted to the nematode species normally associated with the particular bacterial strain. The patterns of adhesion observed suggested that a range of different adhesin-receptor interactions may be involved. Both D. alopecuri spore samples adhered to varying degrees to all the nematode populations. The observed adhesion patterns showed some relationship to the taxonomic and geographic groupings of the organisms. The specificity of the associations of these pathogens in vivo seems only in part due to specificity of adhesion to the vector nematodes but may also be influenced by other factors such as the ability to colonize alternate hosts and/or lack of geographical overlap with other potential vectors.