Rapid identification of cyst (Heterodera spp., Globodera spp.) and root-knot (Meloidogyne spp.) nematodes on the basis of ITS2 sequence variation detected by PCR-single-strand conformational polymorphism (PCR-SSCP) in cultures and field samples

Cyst and root-knot nematodes show high levels of gross morphological simila rity. This presents difficulties for the study of their ecology in natural ecosystems. In this study, cyst and root-knot nematode species, as well as some ectoparasitic nematode species, were identified using the second inter nal transcribed spacer (ITS2) sequence variation detected by polymerase cha in reaction-single-strand conformational polymorphism (PCR-SSCP). The ITS2 region was sufficiently variable within the taxa investigated to allow spec ies to be separated on the basis of minor sequence variation. The PCR prime rs used in this study were effective for 12 species with three genera withi n the Heteroderinae (Globodera pallida, G. rostochiensis, Heterodera arenar ia/avenae, H. ciceri, H. daverti, H. hordecalis, PI. mani, PI. schachtii, H . trifolii, Meloidogyne ardenensis, M. duytsi and M. maritima). However, pa thotypes of Globodera pallida and G. rostochiensis could not be distinguish ed. The method was tested at two coastal dune locations in The Netherlands tone in the lime-poor dunes of the north and one in calcareous dunes of the south) to determine the population structure of cyst nematodes. At each si te, cyst nematodes were associated with three plant species: two plant spec ies on the foredune (Elymus farctus and Ammophila arenaria) and one plant s pecies occurring further inland (Calamagrostis epigejos). Two species of cy st nematodes, H. arenaria and H. hordecalis, were found. H. arenaria associ ated with vigorous A. arenaria and H. hordecalis in association with degene rating A. arenaria and C. epigejos. The field survey demonstrated that in c oastal dunes abiotic factors may be the important affecting the distributio n of cyst nematodes.