Compatibility between Pasteuria penetrans isolates and Meloidogyne populations from Spain

Several populations of Pasteuria isolated from fields in Spain were compared with other Pasteuria populations, held in collections at the Institute de Recerca i Tecnologia, Agroalimentaries (IRTA), Cabrils or IACR-Rothamsted, for their ability to adhere to and infect root-knot nematodes (Meloidogyne spp.) grown on host plants differing in their susceptibility to root-knot nematodes. The results showed a high level of variation in bath the ability of a population of Pasteuria to adhere to a particular population of nematode and vice versa. In particular the isolates of Pasteuria originating from M. hapla retained a high level of specificity for the species from which they originated. The infection of the nematodes by the bacteria was generally low, even when nematodes were encumbered with relatively high levels of spores. It is suggested that prolonged storage (6 years) may reduce the ability of spores to infect nematodes independently of adhesion.