title: Genome-wide delineation of natural variation for pod shatter resistance in Brassica napus.
abstract: Resistance to pod shattering (shatter resistance) is a target trait for global rapeseed (canola, Brassica napus L.), improvement programs to minimise grain loss in the mature standing crop, and during windrowing and mechanical harvest. We describe the genetic basis of natural variation for shatter resistance in B. napus and show that several quantitative trait loci (QTL) control this trait. To identify loci underlying shatter resistance, we used a novel genotyping-by-sequencing approach DArT-Seq. QTL analysis detected a total of 12 significant QTL on chromosomes A03, A07, A09, C03, C04, C06, and C08; which jointly account for approximately 57% of the genotypic variation in shatter resistance. Through Genome-Wide Association Studies, we show that a large number of loci, including those that are involved in shattering in Arabidopsis, account for variation in shatter resistance in diverse B. napus germplasm. Our results indicate that genetic diversity for shatter resistance genes in B. napus is limited; many of the genes that might control this trait were not included during the natural creation of this species, or were not retained during the domestication and selection process. We speculate that valuable diversity for this trait was lost during the natural creation of B. napus. To improve shatter resistance, breeders will need to target the introduction of useful alleles especially from genotypes of other related species of Brassica, such as those that we have identified.
authors.affiliation: Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
authors.forename: Harsh
authors.initials: H
authors.lastname: Raman
authors.affiliation: Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
authors.forename: Rosy
authors.initials: R
authors.lastname: Raman
authors.affiliation: Diversity Arrays Technology Pty Ltd, University of Canberra, Bruce, ACT, Australia.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kilian
authors.affiliation: Diversity Arrays Technology Pty Ltd, University of Canberra, Bruce, ACT, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Detering
authors.affiliation: Diversity Arrays Technology Pty Ltd, University of Canberra, Bruce, ACT, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Carling
authors.affiliation: Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
authors.forename: Neil
authors.initials: N
authors.lastname: Coombes
authors.affiliation: University of Wollongong, Wollongong, NSW, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Diffey
authors.affiliation: NSW Department of Primary Industries, Tamworth Agricultural Institute, Tamworth, NSW, Australia.
authors.forename: Gururaj
authors.initials: G
authors.lastname: Kadkol
authors.affiliation: Australian Centre for Plant Functional Genomic, School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, Australia; School of Plant Biology, University of Western Australia, Perth, WA, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Edwards
authors.affiliation: CSIRO Division of Plant Industries, Canberra, ACT, Australia.
authors.forename: Margaret
authors.initials: M
authors.lastname: McCully
authors.affiliation: Australian Centre for Plant Functional Genomic, School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, Australia; International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Andhra Pradesh, India.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Ruperao
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, Canada.
authors.forename: Isobel A P
authors.initials: IA
authors.lastname: Parkin
authors.affiliation: School of Plant Biology, University of Western Australia, Perth, WA, Australia; School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Batley
authors.affiliation: Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Luckett
authors.affiliation: Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
authors.forename: Neil
authors.initials: N
authors.lastname: Wratten
mesh_terms: D029688:Brassica napus / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D002874:Chromosome Mapping; D017343:Genes, Plant; D056726:Genetic Association Studies; D005819:Genetic Markers; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D012639:Seeds / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology
chemical_list: D005819:Genetic Markers