title: Breeding signature of combining ability improvement revealed by a genomic variation map from recurrent selection population in Brassica napus.
abstract: Combining ability is crucial for parent selection in crop hybrid breeding. The present investigation and results had revealed the underlying genetic factors which might contribute in adequate combining ability, further assisting in enhancing heterosis and stability. Here, we conducted a large-scale analysis of genomic variation in order to define genomic regions affecting the combining ability in recurrent selection population of rapeseed. A population of 175 individuals was genotyped with the Brassica60K SNP chip. 525 hybrids were assembled with three different testers and used to evaluate the general combining ability (GCA) in three environments. By detecting the changes of the genomic variation, we identified 376 potential genome regions, spanning 3.03% of rapeseed genome which provided QTL-level resolution on potentially selected variants. More than 96% of these regions were located in the C subgenome, indicating that C subgenome had sustained stronger selection pressure in the breeding program than the A subgenome. In addition, a high level of linkage disequilibrium in rapeseed genome was detected, suggesting that marker-assisted selection for the population improvement might be easily implemented. This study outlines the evidence for high GCA on a genomic level and provided underlying molecular mechanism for recurrent selection improvement in B. napus.
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Xinwang
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Bao
authors.initials: B
authors.lastname: Li
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Ka
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Kaining
authors.initials: K
authors.lastname: Hu
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
authors.affiliation: Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Wuhan 430070, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
mesh_terms: D029688:Brassica napus / Q000235:genetics* / Q000502:physiology*; D014644:Genetic Variation; D018745:Genome, Plant; D005838:Genotype; D006823:Hybrid Vigor; D015810:Linkage Disequilibrium; D010641:Phenotype; D000069600:Plant Breeding; D020641:Polymorphism, Single Nucleotide