title: Anthesis date mainly explained correlations between post-anthesis leaf senescence, grain yield, and grain protein concentration in a winter wheat population segregating for flowering time QTLs.
abstract: The genetic variability of the duration of leaf senescence during grain filling has been shown to affect both carbon and nitrogen acquisition. In particular, maintaining green leaves during grain filling possibly leads to increased grain yield, but its associated effect on grain protein concentration has not been studied. The aim of this study was to dissect the genetic factors contributing to correlations observed at the phenotypic level between leaf senescence during grain filling, grain protein concentration, and grain yield in winter wheat. With this aim in view, an analysis of quantitative trait locus (QTL) co-locations for these traits was carried out on a doubled haploid mapping population grown in a large multienvironment trial network. Pleiotropic QTLs affecting leaf senescence and grain yield and/or grain protein concentration were identified on chromosomes 2D, 2A, and 7D. These were associated with QTLs for anthesis date, showing that the phenotypic correlations with leaf senescence were mainly explained by flowering time in this wheat population. Study of the allelic effects of these pleiotropic QTLs showed that delaying leaf senescence was associated with increased grain yield or grain protein concentration depending on the environments considered. It is proposed that this differential effect of delaying leaf senescence on grain yield and grain protein concentration might be related to the nitrogen availability during the post-anthesis period. It is concluded that the benefit of using leaf senescence as a selection criterion to improve grain protein concentration in wheat cultivars may be limited and would largely depend on the targeted environments, particularly on their nitrogen availability during the post-anthesis period.
authors.affiliation: INRA, UMR 1095 Génétique, Diversité et Ecophysiologie des Céréales, 234 Avenue du Brézet, F-63100 Clermont-Ferrand, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Bogard
authors.forename: Matthieu
authors.initials: M
authors.lastname: Jourdan
authors.forename: Vincent
authors.initials: V
authors.lastname: Allard
authors.forename: Pierre
authors.initials: P
authors.lastname: Martre
authors.forename: Marie Reine
authors.initials: MR
authors.lastname: Perretant
authors.forename: Catherine
authors.initials: C
authors.lastname: Ravel
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Heumez
authors.forename: Simon
authors.initials: S
authors.lastname: Orford
authors.forename: John
authors.initials: J
authors.lastname: Snape
authors.forename: Simon
authors.initials: S
authors.lastname: Griffiths
authors.forename: Oorbessy
authors.initials: O
authors.lastname: Gaju
authors.forename: John
authors.initials: J
authors.lastname: Foulkes
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Gouis
mesh_terms: D002523:Edible Grain / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D005838:Genotype; D006238:Haploidy; D016014:Linear Models; D009584:Nitrogen / Q000378:metabolism; D040641:Quantitative Trait Loci / Q000235:genetics; D014908:Triticum / Q000235:genetics*
chemical_list: D009584:Nitrogen