title: A multiparental cross population for mapping QTL for agronomic traits in durum wheat (Triticum turgidum ssp. durum).
abstract: Multiparental cross designs for mapping quantitative trait loci (QTL) provide an efficient alternative to biparental populations because of their broader genetic basis and potentially higher mapping resolution. We describe the development and deployment of a recombinant inbred line (RIL) population in durum wheat (Triticum turgidum ssp. durum) obtained by crossing four elite cultivars. A linkage map spanning 2664 cM and including 7594 single nucleotide polymorphisms (SNPs) was produced by genotyping 338 RILs. QTL analysis was carried out by both interval mapping on founder haplotype probabilities and SNP bi-allelic tests for heading date and maturity date, plant height and grain yield from four field experiments. Sixteen QTL were identified across environments and detection methods, including two yield QTL on chromosomes 2BL and 7AS, with the former mapped independently from the photoperiod response gene Ppd-B1, while the latter overlapped with the vernalization locus VRN-A3. Additionally, 21 QTL with environment-specific effects were found. Our results indicated a prevalence of environment-specific QTL with relatively small effect on the control of grain yield. For all traits, functionally different QTL alleles in terms of direction and size of genetic effect were distributed among parents. We showed that QTL results based on founder haplotypes closely matched functional alleles at known heading date loci. Despite the four founders, only 2.1 different functional haplotypes were estimated per QTL, on average. This durum wheat population provides a mapping resource for detailed genetic dissection of agronomic traits in an elite background typical of breeding programmes.
authors.affiliation: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Sara Giulia
authors.initials: SG
authors.lastname: Milner
authors.affiliation: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Maccaferri
authors.affiliation: Digital Productivity Flagship and Agriculture Flagship, CSIRO, St Lucia, Qld, Australia.
authors.forename: Bevan Emma
authors.initials: BE
authors.lastname: Huang
authors.affiliation: Società Produttori Sementi Bologna, Argelato, Bologna, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Mantovani
authors.affiliation: Società Produttori Sementi Bologna, Argelato, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Massi
authors.affiliation: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Frascaroli
authors.affiliation: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tuberosa
authors.affiliation: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Silvio
authors.initials: S
authors.lastname: Salvi
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping / Q000379:methods*; D003198:Computer Simulation; D003433:Crosses, Genetic; D008040:Genetic Linkage; D005819:Genetic Markers; D014644:Genetic Variation; D018745:Genome, Plant; D006239:Haplotypes / Q000235:genetics; D007178:Inbreeding; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D014908:Triticum / Q000033:anatomy & histology / Q000235:genetics*
chemical_list: D005819:Genetic Markers
keywords: QTL; SNP; Triticum turgidum; agronomic traits; founder haplotypes; multiparental cross