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

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.

Use of a trap garden to find additional genetically distinct isolates of the rust fungus Phragmidium violaceum to enhance biological control of European blackberry in Australia

“…Evans et al (2011) observed that only a few uredinia developed on this clone after inoculation with isolate F15. The lack of a relationship between pathogenicity and molecular data in our study was not surprising and has been observed for other rust pathogens (Villaréal et al 2002;Keiper et al 2003).…”

Discovery of multiple IGS haplotypes within genotypes of Puccinia striiformis

“…Many molecular markers have been used in the study of wheat stripe rust, such as dsRNA, RAPD, RFLP, and AFLP, but few or no polymorphisms have been found, and these generally show no relationship to different pathotypes (Villar eal et al 2002). Roose-Amsaleg et al (2002) were the first to find IGS1 length polymorphism in P. striiformis f. sp.…”

“…Amplified restriction fragment length polymorphism (AFLP) can reveal high levels of polymorphism and is considered a robust method to study genetic diversity of wheat yellow rust (Villar eal et al 2002;Becerra et al 2007;Liu et al 2011), to understand the evolution of pathotypes (Zheng et al 2001), and to trace back aerial dispersal of this pathogen to other geographical regions Enjalbert et al 2005). AFLP markers have revealed a clonal population in Northwestern Europe , and no amplified fragment length polymorphisms were found among Australian and New Zealand isolates (Steele et al 2001).…”

Identification of wheat proteins with altered expression levels in leaves infected by the stripe rust pathogen

“…tritici (Pst) is a destructive disease of wheat (Triticum aestivum L.) worldwide (Saari and Prescott 1985;Hau and de VallavieillePope 1998;Villareal et al 2002). In China, it is the most serious foliar disease of wheat and can cause up to 40% losses in yield (Li and Zeng 2002).…”