Molecular techniques to identify Meloidogyne hapla, M. chitwoodi, M. fallax and other Meloidogyne species
1) A fast PCR-technique has been developed in the Netherlands to identify specifically M. hapla, M. chitwoodi (EPPO A2 quarantine pest), M. fallax. By using a mixture of 4 primers in a single PCR reaction, it is possible to identify single juveniles or isolates of these four species. This technique also allows the detection of species present in mixtures, in proportions as low as 2 to 5 % (Ziljstra, 1997).
Note: In this study, several isolates of the four species from various countries have been used. Among them, an isolate of M. chitwoodi from Portugal and an isolate of M. fallax from Belgium are mentioned. The EPPO Secretariat had previously no data on the occurrence of these species in Portugal and Belgium.
2) Another molecular technique using PCR with 5 primers (specific and non specific) has been developed and allows to identify M. chitwoodi and M. fallax specifically, and to differentiate them from M. hapla, M. incognita, M. javanica, M. arenaria and M. mayaguensis (Petersen et al., 1997).
Sources
Petersen, D.; Zijlstra, C. Wishart, J.; Blok, V.; Vrain, T. (1997) Specific probes efficiently distinguish root-knot nematodes species using signature sequences in the ribosomal intergenic spacer.
Fundamental and applied Nematology, 20(6), 619-626.
Zijlstra, C. (1997) A fast PCR assay to identify Meloidogyne hapla, M. chitwoodi and M. fallax, and to sensitively differentiate them from each other and from M. incognita in mixtures.
Fundamental and applied Nematology, 20(5), 505-511.