A species-specific DNA probe for the identification of Meloidogyne hapla

Here we report the development of a DNA probe specific to Meloidogyne hapla , among four species in the genus that we have studied. A small-insert geno mic library from an isolate of M hapla was constructed in the pBluescript v ector. From the library. 3 200 clones were differentially screened against genomic DNA from Al. arenaria, M. incognita and M. javanica. About 99% of t he clones hybridized positively to the three nematode species. The clones t hat hybridized specifically to the genomic DNA from different ill. hapla is olates were selected and further characterized by slot-blot and Southern bl ot analyses. Sequence analysis froth one of the clones reveals a 171 by A a nd T-rich DNA insert, and a 55-base DNA oligonucleotide specific to M hapla isolates.