title: Validation of QTL for resistance to Aphanomyces euteiches in different pea genetic backgrounds using near-isogenic lines.
abstract: Marker-assisted backcrossing was used to generate pea NILs carrying individual or combined resistance alleles at main Aphanomyces resistance QTL. The effects of several QTL were successfully validated depending on genetic backgrounds. Quantitative trait loci (QTL) validation is an important and often overlooked step before subsequent research in QTL cloning or marker-assisted breeding for disease resistance in plants. Validation of QTL controlling partial resistance to Aphanomyces root rot, one of the most damaging diseases of pea worldwide, is of major interest for the future development of resistant varieties. The aim of this study was to validate, in different genetic backgrounds, the effects of various resistance alleles at seven main resistance QTL recently identified. Five backcross-assisted selection programs were developed. In each, resistance alleles at one to three of the seven main Aphanomyces resistance QTL were transferred into three genetic backgrounds, including two agronomically important spring (Eden) and winter (Isard) pea cultivars. The subsequent near-isogenic lines (NILs) were evaluated for resistance to two reference strains of the main A. euteiches pathotypes under controlled conditions. The NILs carrying resistance alleles at the major-effect QTL Ae-Ps4.5 and Ae-Ps7.6, either individually or in combination with resistance alleles at other QTL, showed significantly reduced disease severity compared to NILs without resistance alleles. Resistance alleles at some minor-effect QTL, especially Ae-Ps2.2 and Ae-Ps5.1, were also validated for their individual or combined effects on resistance. QTL × genetic background interactions were observed, mainly for QTL Ae-Ps7.6, the effect of which increased in the winter cultivar Isard. The pea NILs are a novel and valuable resource for further understanding the mechanisms underlying QTL and their integration in breeding programs.
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Lavaud
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|Terres Univia, 11 rue de Monceau, CS 60003, 75378, Paris Cedex 08, France.
authors.forename: A
authors.initials: A
authors.lastname: Lesné
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Piriou
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Le Roy
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Boutet
authors.affiliation: PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|Terres Inovia, 11 rue de Monceau, CS 60003, 75378, Paris Cedex 08, France.
authors.forename: A
authors.initials: A
authors.lastname: Moussart
authors.affiliation: INRA, UMR GDEC 1095, Génétique, Diversité, Ecophysiologie des Céréales, 5 chemin de Beaulieu, 63039, Clermont-Ferrand Cedex 2, France.
authors.forename: C
authors.initials: C
authors.lastname: Poncet
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: R
authors.initials: R
authors.lastname: Delourme
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.|PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Baranger
authors.affiliation: INRA, UMR IGEPP 1349, Institut de Génétique, Environnement et Protection des Plantes, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France. marie-laure.pilet@rennes.inra.fr.|PISOM, UMT INRA/Terres Inovia, UMR IGEPP 1349, Domaine de la Motte au Vicomte, BP 35327, 35653, Le Rheu Cedex, France. marie-laure.pilet@rennes.inra.fr.
authors.forename: M-L
authors.initials: ML
authors.lastname: Pilet-Nayel
mesh_terms: D000483:Alleles; D044744:Aphanomyces / Q000472:pathogenicity; D003433:Crosses, Genetic; D018744:DNA, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D000068617:Genetic Background; D005819:Genetic Markers; D005838:Genotype; D007178:Inbreeding; D018532:Pisum sativum / Q000235:genetics* / Q000382:microbiology; D010641:Phenotype; D000069600:Plant Breeding; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers