title: Genetic effects and genotype × environment interactions govern seed oil content in Brassica napus L.
abstract: As seed oil content (OC) is a key measure of rapeseed quality, better understanding the genetic basis of OC would greatly facilitate the breeding of high-oil cultivars. Here, we investigated the components of genetic effects and genotype × environment interactions (GE) that govern OC using a full diallel set of nine parents, which represented a wide range of the Chinese rapeseed cultivars and pure lines with various OCs.
  
  
  
  Our results from an embryo-cytoplasm-maternal (GoCGm) model for diploid seeds showed that OC was primarily determined by genetic effects (VG) and GE (VGE), which together accounted for 86.19% of the phenotypic variance (VP). GE (VGE) alone accounted for 51.68% of the total genetic variance, indicating the importance of GE interaction for OC. Furthermore, maternal variance explained 75.03% of the total genetic variance, embryo and cytoplasmic effects accounted for 21.02% and 3.95%, respectively. We also found that the OC of F1seeds was mainly determined by maternal effect and slightly affected by xenia. Thus, the OC of rapeseed was simultaneously affected by various genetic components, including maternal, embryo, cytoplasm, xenia and GE effects. In addition, general combining ability (GCA), specific combining ability (SCA), and maternal variance had significant influence on OC. The lines H2 and H1 were good general combiners, suggesting that they would be the best parental candidates for OC improvement. Crosses H3 × M2 and H1 × M3 exhibited significant SCA, suggesting their potentials in hybrid development.
  
  
  
  Our study thoroughly investigated and reliably quantified various genetic factors associated with OC of rapeseed by using a full diallel and backcross and reciprocal backcross. This findings lay a foundation for future genetic studies of OC and provide guidance for breeding of high-oil rapeseed cultivars.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Center for Plant Genetics and Breeding, School of Plant Biology, the University of Western Australia (M080), 35 Stirling Highway, Crawley, WA, 6009, Australia. ping.si@uwa.edu.au.
authors.forename: Ping
authors.initials: P
authors.lastname: Si
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic 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, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.affiliation: National Key Laboratory of Crop Genetic 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, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
authors.affiliation: National Research Council Canada, Saskatoon, Saskatchewan, S7N 0W9, Canada.
authors.forename: Jitao
authors.initials: J
authors.lastname: Zou
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China. jxshen@mail.hzau.edu.cn.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
mesh_terms: D029688:Brassica napus / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics; D059647:Gene-Environment Interaction; D014644:Genetic Variation; D005838:Genotype; D010641:Phenotype; D010938:Plant Oils / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism*
chemical_list: D010938:Plant Oils
keywords: Brassica napus; Diallel; Genetic effects; Seed oil content