Cuticle heterogeneity as exhibited by Pasteuria spore attachment is not linked to the phylogeny of parthenogenetic root-knot nematodes (Meloidogyne spp.)

The cuticle is a major barrier prohibiting the infection of nematodes again st micro-organisms. The attachment of bacterial spores of the nematode hype rparasite Pasteuria penetrans (PPI) to field populations of root-knot nemat odes (RKN, Meloidogyne spp.) from Burkino Faso, Ecuador, Greece, Malawi. Se negal and Trinidad and Tobago were assayed in standard attachment tests. Th e attachment of spore population PP1 to different field populations of root -knot nematode showed that the rates of attachment differed between countri es. Similar tests were also undertaken on f. penetrans spores from these co untries against 2 species of RKN, M. incognita and M. arenaria. The results show ed a high degree of variability in spore attachment with no clear dis tinction between the 2 species of nematode. It has been hypothesized that P asteuria spore attachment is linked to nematode species designations and th is study clearly shows that this is not the case. Further tests showed that variation in spore attachment was not linked to nematode phylogeny. The re sults therefore beg the question of how do parthenogenetic root-knot nemato des maintain cuticle variability in the face of such an aggressive hyperpar asite.