Identification of plant parasitic nematodes by PCR amplification of DNA fragments.

A study concerning the detection and characterization of a DNA fragment from plant-parasitic nematodes to be used as a molecular marker for the identification of different nematodes is described. A fragment of DNA, which is known to consist of a variable region flanked by two conserved regions, has been studied by using PCR amplification. A portion of about 600 nucleotides at the 5'end of the larger rRNA gene has been amplified in different nematodes, using heterologous primers which hybridize with the conserved regions. The results obtained clearly indicate that the same primers can be used for the amplification of this segment in nematodes of different species and of different genera: Meloidogyne artiellia, M. incognita, Xiphinema index, X. diversicaudatum and Globodera pallida. The amplified regions have been partially sequenced. The nucleotide sequences have been analysed by comparison with the published sequence of Caenorhabditis elegans.