Petal colour is considered as an important trait and major visual signal for insect‐pollinated plants and landscaping. In previous study, we isolated and identified two genes (BnPC1 and BnPC2) that control the orange petal colour (OPC) in rapeseed. To identify the molecular markers linked to the orange petal colour, we constructed a B. napus linkage map with four newly developed simple sequence repeat (SSR) markers and nine insertion–deletion (InDel) markers using BC₅II, a near isogenic line population segregated at the BnPC2 locus. The BnPC2 gene was flanked by Indel‐3 and Indel‐20 and was found to represent a 27‐kb (3.721–3.748 Mb) region on A09 of B. napus. High‐pressure liquid chromatography analysis revealed that, compared to yellow petals, orange petals exhibit significantly increased zeaxanthin, β‐carotene and lutein contents and a relatively decreased violaxanthin content. Expression profiling confirmed that BnaA09.ZEP (zeaxanthin epoxidase) is an important candidate gene for BnPC2 and is predominantly expressed in floral tissues. Overall, our results provide a basis for understanding the molecular mechanisms underlying the orange petal colour trait in B. napus.

中文翻译：

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春季油菜中橙色花瓣颜色基因Bnpc2的精细定位及候选基因分析

花瓣颜色被认为是昆虫授粉植物和景观美化的重要特征和主要视觉信号。在以前的研究中，我们分离并鉴定了两个控制油菜中橙色花瓣颜色（OPC）的基因（BnPC1和BnPC2）。为了鉴定与橙色花瓣颜色相关的分子标记，我们使用BC ₅ II（一种近等基因系种群）构建了一个B. napus连锁图，其中包含四个新开发的简单序列重复（SSR）标记和九个插入-缺失（InDel）标记。分离在BnPC2基因座处。所述BnPC2基因通过个Indel-3和个Indel-20两侧并发现表示上的一个A09 27-kb的（3.721-3.748 MB）区域甘蓝型油菜。高压液相色谱分析显示，与黄色花瓣相比，橙色花瓣的玉米黄质，β-胡萝卜素和叶黄素含量显着增加，而紫黄质含量相对降低。表达谱证实，BnaA09.ZEP（玉米黄质环氧）是一个重要的候选基因BnPC2和花组织主要表达。总的来说，我们的结果为理解油菜橙花瓣颜色特征的分子机制提供了基础。