title: High-resolution mapping of genes involved in plant stage-specific partial resistance of barley to leaf rust.
abstract: Partial resistance quantitative trait loci (QTLs)Rphq11andrphq16againstPuccinia hordeiisolate 1.2.1 were previously mapped in seedlings of the mapping populations Steptoe/Morex and Oregon Wolfe Barleys, respectively. In this study, QTL mapping was performed at adult plant stage for the two mapping populations challenged with the same rust isolate. The results suggest thatRphq11andrphq16are effective only at seedling stage, and not at adult plant stage. The cloning of several genes responsible for partial resistance of barley toP. hordeiwill allow elucidation of the molecular basis of this type of plant defence. A map-based cloning approach requires to fine-map the QTL in a narrow genetic window. In this study,Rphq11andrphq16were fine-mapped using an approach aiming at speeding up the development of plant material and simplifying its evaluation. The plant materials for fine-mapping were identified from early plant materials developed to produce QTL-NILs. The material was first selected to carry the targeted QTL in heterozygous condition and susceptibility alleles at other resistance QTLs in homozygous condition. This strategy took four to five generations to obtain fixed QTL recombinants (i.e., homozygous resistant at theRphq11orrphq16QTL alleles, homozygous susceptible at the non-targeted QTL alleles). In less than 2 years,Rphq11was fine-mapped into a 0.2-cM genetic interval and a 1.4-cM genetic interval forrphq16. The strongest candidate gene forRphq11is a phospholipid hydroperoxide glutathione peroxidase. Thus far, no candidate gene was identified forrphq16.
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.|Department of Plant Science and Environmental Ecology, Faculty of Resource Science and Technology, University Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia.
authors.forename: F K S
authors.initials: FKS
authors.lastname: Yeo
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Bouchon
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Kuijken
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Loriaux
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-4660 USA.
authors.forename: C
authors.initials: C
authors.lastname: Boyd
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.
authors.forename: R E
authors.initials: RE
authors.lastname: Niks
authors.affiliation: Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, 6700 AJ Wageningen, the Netherlands.|UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France.
authors.forename: T C
authors.initials: TC
authors.lastname: Marcel
keywords: Barley; High resolution mapping; Puccinia; Quantitative trait locus (QTL); Resistance