Titre original
Genetic variability in Puccinia striiformis f. sp. tritici populations sampled on a local scale during natural epidemics
Références :
Applied and Environmental Microbiology (2002) 6138-6145
Auteurs :
Premier auteur : Villareal, Lorys
Seconds auteurs :Lannou, Christian ; de Vallavieille-Pope, Claude ; Neema, Claire
Laboratoire de recherche :
Laboratoire de Pathologie Végétale, INRA-INAPG, Paris, France
Abstract :
This study investigated genetic polymorphism on a local scale in Puccinia styriiformis 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 analysed 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.
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