title: A major gene mapped on chromosome XII is the main factor of a quantitatively inherited resistance to Meloidogyne fallax in Solanum sparsipilum.
abstract: Meloidogyne fallax is an emerging pest in Europe and represents a threat for potato production. We report the mapping of genetic factors controlling a quantitative resistance against M. fallax identified in the Solanum sparsipilum genotype 88S.329.15. When infected, this genotype develops a necrotic reaction at the feeding site of the juveniles and totally prevents their development to the female stage. A "F1" diploid progeny consisting of 128 individuals was obtained using the potato (S. tuberosum) dihaploid genotype BF15 H1 as female progenitor. Sixty-eight hybrid genotypes displayed necrosis at the feeding site of the juveniles and 60 other genotypes showed no defence reaction. This suggested a monogenic control of the resistance. However, when considering the number of nematode females developed in their roots, a continuous distribution was observed for both "necrotic" and "non-necrotic" hybrid genotypes, indicating a polygenic control of the resistance. A linkage map of each parental genotype was constructed using AFLP markers. The necrotic reaction (NR) was mapped as a qualitative trait on chromosome XII of the resistant genotype 88S.329.15. Quantitative trait locus (QTL) analysis for the number of nematode females developed per "F1" plant genotype was performed using the QTL cartographer software. No QTL was detected on the linkage map of the susceptible parent. A QTL explaining 94.5% of the phenotypic variation was mapped on chromosome XII of the resistant progenitor. This QTL, named MfaXIIspl, was mapped in a genomic region collinear to the map position of the Mi-3 gene conferring resistance to Meloidogyne incognita in tomato. It corresponds to the NR locus.
authors.affiliation: Biologie des Organismes et des Populations appliquée à la Protection des Plantes (Bio3P), Laboratoire de nématologie, Umr inra-Agrocampus Rennes, Domaine la Motte, BP 35327, 35653 , Le Rheu Cedex, France.
authors.forename: Abou Bakari
authors.initials: AB
authors.lastname: Kouassi
authors.forename: Kouassi Abou
authors.initials: KA
authors.lastname: Bakari
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Kerlan
authors.forename: Kerlan
authors.initials: K
authors.lastname: Marie-Claire
authors.forename: Bernard
authors.initials: B
authors.lastname: Caromel
authors.forename: Caromel
authors.initials: C
authors.lastname: Bernard
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Dantec
authors.forename: Dantec
authors.initials: D
authors.lastname: Jean-Paul
authors.forename: Didier
authors.initials: D
authors.lastname: Fouville
authors.forename: Fouville
authors.initials: F
authors.lastname: Didier
authors.forename: Maria
authors.initials: M
authors.lastname: Manzanares-Dauleux
authors.forename: Manzanares-Dauleux
authors.initials: MD
authors.lastname: Maria
authors.forename: Daniel
authors.initials: D
authors.lastname: Ellissèche
authors.forename: Ellissèche
authors.initials: E
authors.lastname: Daniel
authors.forename: Didier
authors.initials: D
authors.lastname: Mugniéry
authors.forename: Mugniéry
authors.initials: M
authors.lastname: Didier
mesh_terms: D000818:Animals; D016923:Cell Death / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics*; D007113:Immunity, Innate / Q000235:genetics*; D009336:Necrosis; D010935:Plant Diseases / Q000469:parasitology; D040641:Quantitative Trait Loci; D011995:Recombination, Genetic; D032322:Solanum / Q000235:genetics* / Q000469:parasitology; D014431:Tylenchoidea / Q000254:growth & development / Q000472:pathogenicity*