title: Genome-wide association study reveals the genetic architecture of flowering time in rapeseed (Brassica napus L.).
abstract: Flowering time adaptation is a major breeding goal in the allopolyploid species Brassica napus. To investigate the genetic architecture of flowering time, a genome-wide association study (GWAS) of flowering time was conducted with a diversity panel comprising 523 B. napus cultivars and inbred lines grown in eight different environments. Genotyping was performed with a Brassica 60K Illumina Infinium SNP array. A total of 41 single-nucleotide polymorphisms (SNPs) distributed on 14 chromosomes were found to be associated with flowering time, and 12 SNPs located in the confidence intervals of quantitative trait loci (QTL) identified in previous researches based on linkage analyses. Twenty-five candidate genes were orthologous to Arabidopsis thaliana flowering genes. To further our understanding of the genetic factors influencing flowering time in different environments, GWAS was performed on two derived traits, environment sensitivity and temperature sensitivity. The most significant SNPs were found near Bn-scaff_16362_1-p380982, just 13 kb away from BnaC09g41990D, which is orthologous to A. thaliana CONSTANS (CO), an important gene in the photoperiod flowering pathway. These results provide new insights into the genetic control of flowering time in B. napus and indicate that GWAS is an effective method by which to reveal natural variations of complex traits in B. napus.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Xu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Kaining
authors.initials: K
authors.lastname: Hu
authors.affiliation: College of Agronomy, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Zhenqian
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Chunyun
authors.initials: C
authors.lastname: Guan
authors.affiliation: Jiangsu Academy of Agricultural Science, Nanjing 210014, China.
authors.forename: Song
authors.initials: S
authors.lastname: Chen
authors.affiliation: The Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hua
authors.affiliation: Chongqing Engineering Research Center for Rapeseed, College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China.
authors.forename: Jiana
authors.initials: J
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China yibin@mail.hzau.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D029688:Brassica napus / Q000235:genetics* / Q000502:physiology; D035264:Flowers / Q000502:physiology*; D018745:Genome, Plant; D055106:Genome-Wide Association Study; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci
keywords: Brassica napus; SNP; association mapping; flowering time; linkage disequilibrium