Submitted to: Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2009
Publication Date: 9/29/2009
Citation: Deahl, K.L., Perez, F.G., Thompson, J.M., Collier, R., Thompson, S., Cooke, L.R. 2009. Characterization of Phytophthora infestans isolates from Jersey, Channel Islands. Potato Research. 52:341-354. Interpretive Summary: Although it has been more than 160 years since the Irish Potato Famine, the pathogen responsible for these crop epidemics is still causing major losses in the U.K. Therefore, scientists are attempting to understand how this organism changes, survives, and moves around between crops in various countries. This manuscript describes how molecular marker characterization of various strains of the pathogens from the Channel Island of Jersey is helping to explain disease migration routes between the European mainland and the U.K. This information allows us to track changes in late blight populations. This information is essential for fungicide application and continued work in this area will greatly benefit the consumer and the potato farmer.
Technical Abstract: Potato production on the island of Jersey, in the English Channel, is dominated by Jersey Royal, a selection of the early cultivar Royal Kidney. Jersey Royal is very susceptible to Phytophthora infestans, the cause of potato late blight, and Jersey’s climate is frequently conducive to infection. During 2004-2006, isolates of P. infestans were obtained from Jersey Royal from 41 different sites (24 crops, 1 infected tuber, 16 volunteers) and from five outdoor tomato crops and characterized by mating type, mtDNA haplotype, Pep allozyme genotype, metalaxyl resistance and RG57 fingerprint. All but one isolate from potato belonged to a single A1 multilocus genotype or a variant. The five isolates from tomato represented three distinct genotypes none of which was found on potato and included one which was A2 mating type. The populations of P. infestans on potato and tomato in Jersey appear distinct, with that on potato being highly clonal.