A systematic dissection of the mechanisms underlying the natural variation of silique number in rapeseed (Brassica napus L.) germplasm
A systematic dissection of the mechanisms underlying the natural variation of silique number in rapeseed (Brassica napus L.) germplasm
复制标题
油菜种质中角果数自然变异机制的系统剖析
DOI：
10.1111/pbi.13224
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发表时间：
2019-09-17
影响因子：
13.8
通讯作者：
Wang, Hanzhong
中科院分区：
文献类型：
--
作者：
Li, Shuyu;Zhu, Yaoyao;Wang, Hanzhong
摘要 长角果数是油菜籽 (Brassica napus L.) 产量的最重要组成部分。为了剖析油菜种质中角果数自然变异的机制，进行了一系列研究。采用 331 个核心系进行全基因组关联研究 (GWAS)，鉴定出 27 个位点（包括 20 个新位点）。多角果系和少角果系之间的长角果数差异可归因于花数和长角果坐果率的累积差异。两者分别占75.2%和24.8%。长角果数与总光合作用和生物量高度相关。显微分析表明，角果系极多和极少的差异通常发生在花蕾数量上，而不是形态上。茎尖分生组织（SAM）的转录组分析表明，大多数富集群体与生长素生物合成/代谢、营养生长和营养/能量积累有关。通过整合 GWAS 和 RNA-seq 结果，确定了 6 个有前景的候选基因，其中一些与生物量积累有关。综上所述，长角果数的自然变化很大程度上受生物量和营养积累的影响，本质上体现了源库之间的正向调节关系。我们的研究为油菜籽长角果数的自然变异提供了全面、系统的解释，为其改良提供了基础。
Summary Silique number is the most important component of yield in rapeseed (Brassica napus L.). To dissect the mechanism underlying the natural variation of silique number in rapeseed germplasm, a series of studies were performed. A panel of 331 core lines was employed to genome‐wide association study (GWAS), and 27 loci (including 20 novel loci) were identified. The silique number difference between the more‐ and fewer‐silique lines can be attributed to the accumulative differences in flower number and silique setting rate. Each of them accounted for 75.2% and 24.8%, respectively. The silique number was highly associated with the total photosynthesis and biomass. Microscopic analysis showed that the difference between extremely more‐ and fewer‐silique lines normally occurred at the amount of flower bud but not morphology. Transcriptome analysis of shoot apical meristem (SAM) suggested that most of enriched groups were associated with the auxin biosynthesis/metabolism, vegetative growth and nutrition/energy accumulation. By integrating GWAS and RNA‐seq results, six promising candidate genes were identified, and some of them were related to biomass accumulation. In conclusion, the natural variation of silique number is largely affected by the biomass and nutrition accumulation, which essentially reflects the positive regulatory relationship between the source and sink. Our study provides a comprehensive and systematic explanation for natural variation of silique number in rapeseed, which provides a foundation for its improvement.