Characterization of Phytophthora infestans Isolates from Jersey, Channel Islands

摘要

Potato production on the island of Jersey, in the English Channel, is dominated by Jersey Royal, a selection of the early cultivar International 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 plant samples from 41 different sites (24 crops, one infected tuber, 16 volunteers) and from five outdoor tomato crops and characterised by mating type, mtDNA haplotype, Gpi and Pep allozyme genotype, metalaxyl resistance and RG57 fingerprint. A subset of 17 isolates was additionally characterised by simple sequence repeat (SSR). 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.