title: Identification of stable QTLs for seed oil content by combined linkage and association mapping in Brassica napus.
abstract: Seed oil content is an important agricultural trait in rapeseed breeding. Although numerous quantitative trait locus (QTL) have been identified, most of them cannot be applied in practical breeding mainly due to environmental instability or large confidence intervals. The purpose of this study was to identify and validate high quality and more stable QTLs by combining linkage mapping and genome-wide association study (GWAS). For linkage mapping, we constructed two F2populations from crosses of high-oil content (∼50%) lines 6F313 and 61616 with a low-oil content (∼40%) line 51070. Two high density linkage maps spanned 1987cM (1659 bins) and 1856cM (1746 bins), respectively. For GWAS, we developed more than 34,000 high-quality SNP markers based on 227 accessions. Finally, 40 QTLs and 29 associations were established by linkage and association mapping in different environments. After merging the results, 32 consensus QTLs were obtained and 7 of them were identified by both mapping methods. Seven overlapping QTLs covered an average confidence interval of 183kb and explained the phenotypic variation of 10.23 to 24.45%. We further developed allele-specific PCR primers to identify each of the seven QTLs. These stable QTLs should be useful in gene cloning and practical breeding application.
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: sunfengming@caas.cn.
authors.forename: Fengming
authors.initials: F
authors.lastname: Sun
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: liujing@oilcrops.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: huawei@oilcrops.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Hua
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: sunxingchao_lover@126.com.
authors.forename: Xingchao
authors.initials: X
authors.lastname: Sun
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: wangxf12@sina.com.
authors.forename: Xinfa
authors.initials: X
authors.lastname: Wang
authors.affiliation: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, PR China. Electronic address: wanghz@oilcrops.cn.
authors.forename: Hanzhong
authors.initials: H
authors.lastname: Wang
mesh_terms: D029688:Brassica napus / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D017931:DNA Primers; D056726:Genetic Association Studies; D010641:Phenotype; D010938:Plant Oils / Q000378:metabolism*; D040641:Quantitative Trait Loci; D012639:Seeds / Q000235:genetics / Q000378:metabolism
chemical_list: D017931:DNA Primers; D010938:Plant Oils
keywords: Brassica napus; GWAS; Linkage mapping; Quantitative trait locus