Abstract

Species of the Xiphinema americanum-group are among the most damaging nematodes for a diverse range of crops. This group includes 51 nominal species throughout the world. They are very difficult to identify by traditional taxonomic methods. Despite its importance in agriculture, the species composition of this group in many countries, including Chile, remains unknown. In order to identify the species in the central valley of Chile, we studied the morphological, morphometric and molecular diversity of 13 populations. Through classical taxonomic methods two species, X. inaequale and X. peruvianum, were identified with clear differences in the shape of the lip region. The DNA sequences of the ITS of ribosomal genes revealed divergence in the nucleotide sequences of the two species from 7.3% in ITS1 to 14.7% in ITS2. These results confirmed the presence of two distinct species, namely X. peruvianum and X. inaequale, in the northern and southern parts of the central valley of Chile, respectively. PCR-RFLP was developed for rapid species identification of these two species.