New Races of Puccinia striiformis Found in Europe Reveal Race Specificity of Long-Term Effective Adult Plant Resistance in Wheat.

Resistance to Puccinia striiformis was examined in nine wheat recombinant inbred lines (RILs) from a cross between 'Camp Rémy' (resistant parent) and 'Récital' (susceptible parent) using an isolate of a strain common to the northwestern European population before 2011 (old) and two additional isolates, one representing an aggressive and high-temperature-adapted strain (PstS2) and another representing a virulence phenotype new to Europe since 2011 (new). The RILs carried different combinations of quantitative trait loci (QTL) for resistance to P. striiformis.

Quantitative plant resistance in cultivar mixtures: wheat yellow rust as a modeling case study.

Unlike qualitative plant resistance, which confers immunity to disease, quantitative resistance confers only a reduction in disease severity and this can be nonspecific. Consequently, the outcome of its deployment in cultivar mixtures is not easy to predict, as on the one hand it may reduce the heterogeneity of the mixture, but on the other it may induce competition between nonspecialized strains of the pathogen. To clarify the principles for the successful use of quantitative plant resistance in disease management, we built a parsimonious model describing the dynamics of competing pathogen strains spreading through a mixture of cultivars carrying nonspecific quantitative resistance.

The genetics of obligate parthenogenesis in an aphid species and its consequences for the maintenance of alternative reproductive modes.

Although loss of sex is widespread among metazoans, the genetic mechanisms underlying the transition to asexuality are poorly understood. Aphids are good models to address this issue because they frequently show reproductive-mode variation at the species level, involving cyclical parthenogens (CP) that reproduce sexually once a year and obligate parthenogens (OP) that reproduce asexually all year round. Here, we explore the genetic basis of OP in the cereal aphid Sitobion avenae by crossing several genotypes with contrasting reproductive modes and then characterising the reproductive phenotypes of F1 and F2 offspring.

Durable resistance to stripe rust is due to three specific resistance genes in French bread wheat cultivar Apache.

Quantitative resistance is postulated to be more durable than qualitative (R-gene mediated) resistance, which is usually quickly overcome by the pathogen population. Despite its wide use for nearly 10 years in France, the French bread wheat cultivar Apache remains resistant to stripe rust. Here, we investigated the genetic architecture of cv.

Characterization of genetic components involved in durable resistance to stripe rust in the bread wheat 'Renan'.

Stripe rust, caused by Puccinia striiformis f. tritici, is one of the most widespread and destructive wheat diseases in areas where cool temperatures prevail. The wheat cv.

Adult plant resistance-related gene expression in 'Camp Remy' wheat inoculated with Puccinia striiformis.

The French wheat variety 'Camp Remy' (CR) possesses a durable, adult plant resistance to yellow rust (YR), caused by the pathogen Puccinia striiformis. Using cDNA-AFLP on different sets of heterogeneous inbred families (HIFs) derived from the cross CR x Récital, we compared gene expression profiles during one seedling and two adult developmental stages following inoculation with P. striiformis.

Structure of Aegilops ventricosa chromosome 6Nv, the donor of wheat genes Yr17, Lr37, Sr38, and Cre5.

An Aegilops ventricosa Tausch (2n = 28, DvDvNvNv) subtelocentric chromosome added to wheat (Triticum aestivum L.) in a disomic addition line was found to carry the genes for resistance Yr17, Lr37, Sr38, and Cre5 already transferred onto chromosome 2AS of the wheat line VPM1. Previous works demonstrated that this Ae.

Genetic analysis of durable resistance to yellow rust in bread wheat.

Yellow rust, caused by Puccinia striiformis, is one of the most damaging diseases affecting bread wheat in temperate regions. Although resistance to yellow rust is frequently overcome by new virulent races, a durable form of resistance in the French bread wheat Camp Remy (CR) has remained effective since its introduction in 1980. We used 217 F7 recombinant inbred lines (RILs) derived from the cross between CR and the susceptible cultivar Recital to identify and map quantitative trait loci (QTLs) involved in durable yellow rust resistance.

Mapping of quantitative trait loci for field resistance to Fusarium head blight in an European winter wheat.

Fusarium head blight (FHB) caused by Fusarium culmorum is an economically important disease of wheat that may cause serious yield and quality losses under favorable climate conditions. The development of disease-resistant cultivars is the most effective control strategy. Worldwide, there is heavy reliance on the resistance pool originating from Asian wheats, but excellent field resistance has also been observed among European winter wheats.

Study of the relationship between pre-harvest sprouting and grain color by quantitative trait loci analysis in a whitexred grain bread-wheat cross.

In many wheat ( Triticum aestivumL.) growing areas, pre-harvest sprouting (PHS) may cause important damage, and in particular, it has deleterious effects on bread-making quality. The relationship between PHS and grain color is well known and could be due either to the pleiotropic effect of genes controlling red-testa pigmentation ( R) or to linkage between these genes and other genes affecting PHS.

Isolation of a chromosomally engineered durum wheat line carrying the Aegilops ventricosa pchl gene for resistance to eyespot.

The chromosome 7Dv of Aegilops ventricosa (syn. Triticum ventricosum, 2n = 4x = 28, genome DvDvMvMv) carries the gene Pch1 for resistance to eyespot. This gene has previously been transferred to chromosome 7D of bread wheat, T.

Molecular markers linked to the leaf rust resistance gene Lr24 in different wheat cultivars.

The aim of this study was to find molecular markers (RAPD and SCAR) for the wheat leaf rust resistance gene Lr24. A backcross line, RL 6064, possessing a single resistance gene to leaf rust (Lr24) and its recurrent parent 'Thatcher' were used to find RAPD markers linked to the Lr24 gene. Among 125 RAPD primers tested, only one (OP-H5) detected an additional band in the resistant line RL 6064.