Panglobal distribution of a single clonal lineage of the Irish potato famine fungus.

Abstract

More than 300

AFLP analysis reveals a clonal population of Phytophthora pinifolia in Chile

“…The clonal nature of the pathogen population provides compelling evidence that the pathogen has spread rapidly from a single entry point, with the first detection in Raqui in 2004 (Durán et al 2008). The population structure of P. pinifolia observed in this paper is indicative of an introduced pathogen population (Goodwin et al 1994;Loo, 2009).…”

“…This difference is equivalent to 0.5 % of the scored bands and is a much lower level of diversity than that found in other Phytophthora spp. such as P. infestans (Goodwin et al 1994), Phytophthora cinnamomi (Linde et al 1997;Linde et al 1999) and P. ramorum (Ivors et al 2004;Ivors et al, 2006) that have been defined as clonal. The missing band in isolates CMW 33987 and CMW 34012 could be a consequence of a single mutation in one of the restriction enzyme sites in these two P. pinifolia strains.…”

“…It is typical for introduced pathogens to have very limited genetic diversity. For example, P. infestans spread around the world as a single genotype for more than 100 y (Goodwin et al, 1994;Goodwin and Drenth 1997). Phytophthora ramorum in the USA and Europe and P. cinnamomi in Australia and South Africa are also introduced pathogens showing low levels of genetic diversity (Linde et al 1997;Ivors et al 2006;Prospero et al 2007).…”

Molecular tracking new migrations of an old pathogen : the re-emergence of potato late blight

“…Récent analyses with molecular markers hâve shown that thèse initial migrations probably occurred in three steps (Goodwin 1997;Goodwin et al 1994b). The first step probably was from Mexico to the USA during or shortly before 1843.…”

“…This migration may hâve included a number of génotypes, although it probably did not include the A2 mating type (Goodwin et al 1994a). The second step probably was from the USA to Europe in cultivated potato tubers during 1844 or 1845 and may hâve included only a single génotype, US-1 (Goodwin et al 1994b). The third step probably was from Europe to the rest of the world in seed or ware potatoes beginning after 1845 (summarized in Goodwin 1997).…”