Shen Yusen, Xiang Yang, Xu Ensheng, Ge Xianhong, Li Zaiyun
National Key Laboratory of Crop Genetic Improvement, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Guizhou Rapeseed Institute, Guizhou Academy of Agricultural Sciences, Guiyang, China.
Front Plant Sci. 2018 Mar 28;9:390. doi: 10.3389/fpls.2018.00390. eCollection 2018.
Plant height (PH), branch initiation height (BIH), and stem diameter (SD) are three stem-related traits that play crucial roles in plant architecture and lodging resistance. Herein, we show one doubled haploid (DH) population obtained from a cross between Y689 (one - derived intertribal introgression) and Westar (. cultivar) that these traits were significantly positively correlated with one another and with flowering time (FT). Based on a high-density SNP map, a total of 102 additive quantitative trait loci (QTL) were identified across six environments. Seventy-two consensus QTL and 49 unique QTL were identified using a two-round strategy of QTL meta-analysis. Notably, a total of 19 major QTL, including 11 novel ones, were detected for these traits, which comprised two QTL clusters on chromosomes A02 and A07. Conditional QTL mapping was performed to preliminarily evaluate the genetic basis (pleiotropy or tight linkage) of the co-localized QTL. In addition, QTL by environment interactions (QEI) mapping was performed to verify the additive QTL and estimate the QEI effect. In the genomic regions of all major QTL, orthologs of the genes involved in phytohormone biosynthesis, phytohormone signaling, flower development, and cell differentiation in were proposed as candidate genes. Of these, , an ortholog of , was suggested as a candidate gene for PH, SD, and FT; and , an ortholog of , was associated with PH, BIH and FT. These results provide useful information for further genetic studies on stem-related traits and plant growth adaptation.
株高（PH）、分枝起始高度（BIH）和茎直径（SD）是三个与茎相关的性状，在植物株型和抗倒伏性方面起着关键作用。在此，我们展示了一个从Y689（一个衍生的族间渗入系）和Westar（一个栽培品种）杂交获得的双单倍体（DH）群体，这些性状彼此之间以及与开花时间（FT）均呈显著正相关。基于高密度SNP图谱，在六个环境中总共鉴定出102个加性数量性状位点（QTL）。使用两轮QTL元分析策略鉴定出72个一致QTL和49个独特QTL。值得注意的是，针对这些性状共检测到19个主要QTL，包括11个新的QTL，它们在A02和A07染色体上形成了两个QTL簇。进行了条件QTL定位以初步评估共定位QTL的遗传基础（多效性或紧密连锁）。此外，进行了QTL与环境互作（QEI）定位以验证加性QTL并估计QEI效应。在所有主要QTL的基因组区域中，提出了拟南芥中参与植物激素生物合成、植物激素信号传导、花发育和细胞分化的基因的直系同源基因作为候选基因。其中，拟南芥的直系同源基因被认为是PH、SD和FT的候选基因；以及拟南芥的直系同源基因与PH、BIH和FT相关。这些结果为进一步开展与茎相关性状和植物生长适应性的遗传研究提供了有用信息。
