title: Genetic control of water use efficiency and leaf carbon isotope discrimination in sunflower (Helianthus annuus L.) subjected to two drought scenarios.
abstract: High water use efficiency (WUE) can be achieved by coordination of biomass accumulation and water consumption. WUE is physiologically and genetically linked to carbon isotope discrimination (CID) in leaves of plants. A population of 148 recombinant inbred lines (RILs) of sunflower derived from a cross between XRQ and PSC8 lines was studied to identify quantitative trait loci (QTL) controlling WUE and CID, and to compare QTL associated with these traits in different drought scenarios. We conducted greenhouse experiments in 2011 and 2012 by using 100 balances which provided a daily measurement of water transpired, and we determined WUE, CID, biomass and cumulative water transpired by plants. Wide phenotypic variability, significant genotypic effects, and significant negative correlations between WUE and CID were observed in both experiments. A total of nine QTL controlling WUE and eight controlling CID were identified across the two experiments. A QTL for phenotypic response controlling WUE and CID was also significantly identified. The QTL for WUE were specific to the drought scenarios, whereas the QTL for CID were independent of the drought scenarios and could be found in all the experiments. Our results showed that the stable genomic regions controlling CID were located on the linkage groups 06 and 13 (LG06 and LG13). Three QTL for CID were co-localized with the QTL for WUE, biomass and cumulative water transpired. We found that CID and WUE are highly correlated and have common genetic control. Interestingly, the genetic control of these traits showed an interaction with the environment (between the two drought scenarios and control conditions). Our results open a way for breeding higher WUE by using CID and marker-assisted approaches and therefore help to maintain the stability of sunflower crop production.
authors.affiliation: Université de Toulouse, INP-ENSAT, UMR 1248 AGIR (INPT-INRA), Castanet-Tolosan, France; Brawijaya University, Faculty of Agriculture, Department of Agronomy, Plant Breeding Laboratory, Malang, Indonesia.
authors.forename: Afifuddin Latif
authors.initials: AL
authors.lastname: Adiredjo
authors.affiliation: Université de Toulouse, UPS-Toulouse III, UMR 5126 CESBIO, Toulouse, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Navaud
authors.affiliation: INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR 441, Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes(LIPM), UMR 2594, Castanet-Tolosan, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Muños
authors.affiliation: INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR 441, Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes(LIPM), UMR 2594, Castanet-Tolosan, France.
authors.forename: Nicolas B
authors.initials: NB
authors.lastname: Langlade
authors.affiliation: Université de Toulouse, UPS-Toulouse III, UMR 5126 CESBIO, Toulouse, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Lamaze
authors.affiliation: Université de Toulouse, INP-ENSAT, UMR 1248 AGIR (INPT-INRA), Castanet-Tolosan, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Grieu
mesh_terms: D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000737:chemistry; D055864:Droughts; D008040:Genetic Linkage; D014644:Genetic Variation; D005838:Genotype; D006368:Helianthus / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D014867:Water / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D014867:Water