Silique length influences seed yield in oilseed rape.It shows extensive variation in germplasm resources,and identifying the underlying genes and regulatory mechanisms would advance breeding for the trait.In the prese...Silique length influences seed yield in oilseed rape.It shows extensive variation in germplasm resources,and identifying the underlying genes and regulatory mechanisms would advance breeding for the trait.In the present study,a genome-wide association study(GWAS)using 331 core accessions planted in 10 environments revealed 13 loci associated with silique length on chromosomes A01,A04,A07,A09,and C03,explaining 6.2%–19.2%of phenotypic variance.Physiological analysis showed that silique length variation was attributable to differences in silique growth rate and/or duration before four weeks after flowering,with levels of endogenous phytohormones(auxin,ethylene,and GA24,GA12,and GA44)playing an important role.Cytological analysis showed that silique length variation was due mainly to differences in cell number followed by cell size.Transcriptomic analysis of two pools of silique walls with opposite length extremes revealed 3248 differentially expressed genes(DEGs).These DEGs were enriched in several pathways(such as cell wall,cell division,and hormone metabolism)associated with cell proliferation and expansion and silique development.Integrating GWAS,RNA-seq,and functional annotation results revealed 15 candidate genes for the major associated locus q SL.A09-3.Of these,Bna A9.ARF18 and Bna A9.CYP78 A9 were validated by haplotype analysis followed by candidate gene association.Sequence variation in the coding region of Bna A9.ARF18 and expression of Bna A9.CYP78 A9 in silique walls were strongly associated with silique length.Our results provide an explanation for the natural variation of silique length in oilseed rape germplasm and offer useful information for its improvement.展开更多
基金the Technical Innovation Project of Hubei Province(2018ABA087)National Natural Science Foundation of China(31771840)+2 种基金the China Agriculture Research System of MOF and MARA(CARS-13)the Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2013-OCRI)Fundamental Research Funds for Central Non-Profit Institute of Crop Sciences CAAS(Y2020YJ09)。
文摘Silique length influences seed yield in oilseed rape.It shows extensive variation in germplasm resources,and identifying the underlying genes and regulatory mechanisms would advance breeding for the trait.In the present study,a genome-wide association study(GWAS)using 331 core accessions planted in 10 environments revealed 13 loci associated with silique length on chromosomes A01,A04,A07,A09,and C03,explaining 6.2%–19.2%of phenotypic variance.Physiological analysis showed that silique length variation was attributable to differences in silique growth rate and/or duration before four weeks after flowering,with levels of endogenous phytohormones(auxin,ethylene,and GA24,GA12,and GA44)playing an important role.Cytological analysis showed that silique length variation was due mainly to differences in cell number followed by cell size.Transcriptomic analysis of two pools of silique walls with opposite length extremes revealed 3248 differentially expressed genes(DEGs).These DEGs were enriched in several pathways(such as cell wall,cell division,and hormone metabolism)associated with cell proliferation and expansion and silique development.Integrating GWAS,RNA-seq,and functional annotation results revealed 15 candidate genes for the major associated locus q SL.A09-3.Of these,Bna A9.ARF18 and Bna A9.CYP78 A9 were validated by haplotype analysis followed by candidate gene association.Sequence variation in the coding region of Bna A9.ARF18 and expression of Bna A9.CYP78 A9 in silique walls were strongly associated with silique length.Our results provide an explanation for the natural variation of silique length in oilseed rape germplasm and offer useful information for its improvement.
