Diversity of the bacterial hyperparasite Pasteuria penetrans in relation to root-knot nematodes (Meloidogyne spp.) control on Acacia holosericea

Pasteuria penetrans isolates sampled from different geographical areas were characterised both for the heterogeneity of the endospore surface using mo noclonal antibodies and for the ability of spores to attach to different is olates of Meloidogyne spp. The efficacy of these different Pasteuria isolat es as biological control agents was tested in a glasshouse experiment with M. incognita from Senegal on Acacia holosericea. The immunoprofiles divided the P. penetrans isolates broadly differently from the attachment tests. I solate PP16 from Senegal was associated with better seedling development of M. incognita-inoculated A. holoceria than were other isolates. Substantial variation in root and shoot biomass was not related to the observed variat ion in spore attachment tests. The difficulties involved in obtaining consi stent biological control with Pasteuria are discussed in relation to the hi gh degree of variability of this bacterium.