Molecular variation in the potato cyst nematode, Globodera pallida, in relation to virulence

The potato cyst nematode Globodera pallida poses a challenge for potato growers. The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida cause damage valued at over pounds 50m per annum in the U.K. and problems in controlling PCN are growing due to the increase in populations and spread of G. pallida, the lack of many commercially attractive cultivars with resistance to this species and the pressure to reduce nematicide use. Over 60% of potato fields in the U.K. are infected with G. pallida (Minnis et al. 2000). The Scottish Agricultural Science Agency (SASA) figures show that the incidence of both species of PCN on Scottish seed potato land, though low, has been increasing. The proportion of potato land in ware production in Scotland is also increasing and now represents 50% of the potato growing area. This situation potentially increases the risk of the spread of PCN unless it is very carefully monitored and managed.