Selection for virulence against resistance in the potato cyst nematode Globodera pallida.

The potato cyst nematode (PCN) Globodera pallida is the most economically important nematode pest of the European potato industry. Although the use of natural resistance is the most effective management approach, the existence of multiple pathotypes with different virulence characteristics constitutes a constraint towards this goal. Additionally, the use of resistant varieties may drive strong selection towards virulence. This selection pressure allows the increase in frequency of virulent alleles in the population and therefore, the emergence of highly virulent nematode lineages. In this study, we applied two genomic approaches for the identification of Avirulence (Avr) genes in G. pallida populations selected for high virulence on two main resistance sources, GpaV (from Solanum vernei) and H3 from S. tuberosum ssp. andigena CPC2802.