联合 QTL 作图和转录组测序分析揭示甘蓝型油菜开花时间候选基因

Joint QTL mapping and transcriptome sequencing analysis reveal candidate flowering time genes in Brassica napus L.

机构信息

Chongqing Engineering Research Center for Rapeseed, College of Agronomy and Biotechnology, Southwest University, Academy of Agricultural Sciences, Chongqing, 400715, China.

Plant Genome Mapping Laboratory, University of Georgia, Athens, GA, 30605, USA.

出版信息

BMC Genomics. 2019 Jan 9;20(1):21. doi: 10.1186/s12864-018-5356-8.

BACKGROUND

Optimum flowering time is a key agronomic trait in Brassica napus. To investigate the genetic architecture and genetic regulation of flowering time in this important crop, we conducted quantitative trait loci (QTL) analysis of flowering time in a recombinant inbred line (RIL) population, including lines with extreme differences in flowering time, in six environments, along with RNA-Seq analysis.

RESULTS

We detected 27 QTLs distributed on eight chromosomes among six environments, including one major QTL on chromosome C02 that explained 11-25% of the phenotypic variation and was stably detected in all six environments. RNA-Seq analysis revealed 105 flowering time-related differentially expressed genes (DEGs) that play roles in the circadian clock/photoperiod, autonomous pathway, and hormone and vernalization pathways. We focused on DEGs related to the regulation of flowering time, especially DEGs in QTL regions.

CONCLUSIONS

We identified 45 flowering time-related genes in these QTL regions, eight of which are DEGs, including key flowering time genes PSEUDO RESPONSE REGULATOR 7 (PRR7) and FY (located in a major QTL region on C02). These findings provide insights into the genetic architecture of flowering time in B. napus.

背景

开花时间是油菜中一个重要的农艺性状。为了研究这个重要作物开花时间的遗传结构和遗传调控，我们在六个环境中对包括开花时间差异很大的重组自交系（RIL）群体进行了开花时间的数量性状位点（QTL）分析，并进行了 RNA-Seq 分析。

结果

我们在六个环境中检测到 27 个 QTL 分布在八个染色体上，包括一个位于 C02 染色体上的主效 QTL，解释了 11-25%的表型变异，在所有六个环境中都稳定检测到。RNA-Seq 分析揭示了 105 个与开花时间相关的差异表达基因（DEGs），这些基因在生物钟/光周期、自主途径、激素和春化途径中发挥作用。我们重点研究了与开花时间调控相关的 DEGs，特别是 QTL 区域中的 DEGs。