Genetic Variability in Puccinia striiformis f. sp. tritici Populations Sampled on a Local Scale during Natural Epidemics

• DOI: 10.1128/aem.68.12.6138-6145.2002
• Publication Date: 2002-11-26T00:04:48Z
• Authors: Lorys M. M. A. Vi...; Christian Lannou; Claude de Vallavi...; Claire Neema
• Keywords: 0301 basic medicine; 570; 0303 health sciences; Polymorphism, Genetic; PUCCINIA STRIIFORMIS f.sp.TRITICI; Genotype; Virulence; Basidiomycota; Genetic Variation; MOLECULAR MARKERS; [SDV.EE] Life Sciences [q-bio]/Ecology, environment; 03 medical and health sciences; [SDV.EE]Life Sciences [q-bio]/Ecology; 616; VIRULENCE; environment; Nucleic Acid Amplification Techniques

ABSTRACT

This study investigated genetic polymorphism on a local scale in Puccinia striiformis f. sp. tritici populations during natural epidemics, in four fields located in northern France and sampled in 1998 or 1999. Two hundred and forty-seven isolates were analyzed for their amplified fragment length polymorphism (AFLP) pattern through four primer combinations, and 194 of them were also tested for their virulence factors. Only one or two pathotypes were found in each field, and all isolates had virulence v17, matching the recently introduced Yr17 resistance gene. Polymorphism on a field scale was low. Although 67 loci were polymorphic, 77% of the isolates had the same AFLP pattern, all other patterns being rare or unique. Analyses of the genetic distance between AFLP patterns based on the Jaccard index allowed us to define 12 groups, but a bootstrap analysis showed that all isolates could be assigned to a single clonal lineage. This leads us to conclude that P. striiformis f. sp. tritici populations are clonal on a field scale in northern France.