Molecular approaches to the taxonomic position of Peruvian potato cyst nematodes and gene pool similarities in indigenous and imported populations ofGlobodera

Peruvian potato cyst nematode populations were analysed to assess both thei r inter- and intraspecific similarities. ITS-RFLP and two satellite DNA seq uences were used as taxonomic tools. Both techniques have confirmed that th e Peruvian populations have as their closest relatives the European Globode ra pallida, despite the detection of clear differences that prevents us fro m assigning these South American populations unambiguously to any Globodera species. A more precise study of the variability of these Peruvian populat ions was investigated and they were compared with the imported European pop ulations using protein (2-DGE) and DNA (RAPD) datasets. The clear distincti on between the Peruvian and the European populations was confirmed and, ins ide each group, no correlation was found between the pathotype classificati on and the observed clustering of the populations. Surprisingly, while RAPD s revealed a higher variability in the Peruvian group than in the European one, some characteristic proteins were found by 2-DGE in some European popu lations, whereas it was impossible to find any in the Peruvian populations. It is concluded that the primary founders of the European populations may have an origin other than that of the Peruvian populations involved in this study.