title: De novo genetic variation associated with retrotransposon activation, genomic rearrangements and trait variation in a recombinant inbred line population of Brassica napus derived from interspecific hybridization with Brassica rapa.
abstract: Interspecific hybridization is a significant evolutionary force as well as a powerful method for crop breeding. Partial substitution of the AA subgenome in Brassica napus (A(n) A(n) C(n) C(n) ) with the Brassica rapa (A(r) A(r) ) genome by two rounds of interspecific hybridization resulted in a new introgressed type of B. napus (A(r) A(r) C(n) C(n) ). In this study, we construct a population of recombinant inbred lines of the new introgressed type of B. napus. Microsatellite, intron-based and retrotransposon markers were used to characterize this experimental population with genetic mapping, genetic map comparison and specific marker cloning analysis. Yield-related traits were also recorded for identification of quantitative trait loci (QTLs). A remarkable range of novel genomic alterations was observed in the population, including simple sequence repeat (SSR) mutations, chromosomal rearrangements and retrotransposon activations. Most of these changes occurred immediately after interspecific hybridization, in the early stages of genome stabilization and derivation of experimental lines. These novel genomic alterations affected yield-related traits in the introgressed B. napus to an even greater extent than the alleles alone that were introgressed from the A(r)  subgenome of B. rapa, suggesting that genomic changes induced by interspecific hybridization are highly significant in both genome evolution and crop improvement.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zou
authors.forename: Donghui
authors.initials: D
authors.lastname: Fu
authors.forename: Huihui
authors.initials: H
authors.lastname: Gong
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.forename: J Chris
authors.initials: JC
authors.lastname: Pires
authors.forename: Ruiyuan
authors.initials: R
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Long
authors.forename: Annaliese S
authors.initials: AS
authors.lastname: Mason
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Yang
authors.forename: Yong P
authors.initials: YP
authors.lastname: Lim
authors.forename: Beom S
authors.initials: BS
authors.lastname: Park
authors.forename: Jinling
authors.initials: J
authors.lastname: Meng
mesh_terms: D005075:Biological Evolution; D018533:Biomass; D029688:Brassica napus / Q000235:genetics* / Q000254:growth & development; D029741:Brassica rapa / Q000235:genetics* / Q000254:growth & development; D001947:Breeding; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D015321:Gene Rearrangement / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics*; D005838:Genotype; D006823:Hybrid Vigor; D006824:Hybridization, Genetic / Q000235:genetics*; D007438:Introns / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D030821:Plants, Genetically Modified; D040641:Quantitative Trait Loci; D018626:Retroelements / Q000235:genetics
chemical_list: D018626:Retroelements