title: Quantitative trait loci analysis and genome-wide comparison for silique related traits in Brassica napus.
abstract: BACKGROUND
  Yield of rapeseed is determined by three components: silique number, seed number per silique and thousand seed weight. Seed number per silique and thousand seed weight are influenced by silique length, seed density, silique breadth, silique thickness and silique volume. Some QTLs for silique traits have been reported in B. napus, however, no studies have focused on the six agronomic traits (seed number per silique, silique length, silique breadth, silique thickness, seed density and silique volume) simultaneously, and the genetic determinism of such complex traits have not been fully elucidated.
  
  
  RESULTS
  In this study, the six silique traits were evaluated using 348 lines of a doubled haploid population, the KN population. The results showed that 2, 4, 1, 1 and 2 QTLs explaining > 10 % of phenotypic variation were obtained for silique length, silique breadth, silique thickness, seed number per silique and silique volume, respectively. Notably, three major effect QTLs (cqSB-C6-1, cqSB-C6-2 and cqSV-C6-3) were identified in at least three environments, and 17 unique QTLs controlling at least two traits were obtained. A high-density consensus map containing 1225 markers was constructed for QTL comparison by combining the KN map with other five published maps. The comparative results revealed that 14, 13 and 11 QTLs for silique breadth, silique thickness and silique volume might be the potential new QTLs because few QTLs for these traits were reported in B. napus. In addition, potential new QTLs for silique length (11), seed number per silique (6) and seed density (5) were also identified. Twenty-five candidate genes underlying 27 QTLs for silique related traits were obtained.
  
  
  CONCLUSIONS
  This study constructed QTL analysis in B. napus, and obtained 60 consensus QTLs for six silique related traits. The potential new QTLs will enhance our understanding of the genetic control of silique traits, and the stable QTLs provided the targets for improving seed yield in future. These findings provided comprehensive insights into the genetic network affecting silique traits at QTL level in B. napus.
authors.affiliation: Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.|Provincial Key Laboratory of Agrobiology, Key Laboratory of Cotton and Rapeseed, Ministry of Agriculture, Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.|Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China.
authors.forename: Aina
authors.initials: A
authors.lastname: Wang
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China. wangzy846@sohu.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Tian
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Chao
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Hybrid Rapeseed Research Center of Shaanxi Province, Shaanxi Rapeseed Branch of National Centre for Oil Crops Genetic Improvement, Yangling, 712100, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Gan
authors.affiliation: Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China. limaoteng426@mail.hust.edu.cn.
authors.forename: Maoteng
authors.initials: M
authors.lastname: Li
mesh_terms: D029688:Brassica napus / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D058685:Genetic Pleiotropy; D014644:Genetic Variation; D018745:Genome, Plant; D040641:Quantitative Trait Loci; D012639:Seeds / Q000033:anatomy & histology / Q000235:genetics
keywords: Brassica napus; Candidate genes; Comparative mapping; QTL; Silique traits