THE USE OF HETEROLOGOUS CLONED DNA PROBES TO DISTINGUISH BETWEEN RACES OF MELOIDOGYNE-INCOGNITA

DNA from one population each of the four races of Meloidogyne incognit a was restriction endonuclease digested and Southern blotted onto nitr ocellulose Filters. The filters were probed with a 7kb fragment consis ting of the rDNA repeat of Caenorhabditis elegans (pCe7) and with a 3. 1kb fragment, which contains part of the 18s ribosomal RNA gene from S chistosoma mansoni (pSM389). The results show that not only does rDNA from these species hybridise strongly with all four races of M. incogn ita, but the restriction fragment patterns produced allow the differen tiation of two of the M. incognita races.