National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, National Centre of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan, 430070, China.
BMC Genomics. 2024 Aug 24;25(1):799. doi: 10.1186/s12864-024-10708-1.
As a Brassica crop, Brassica napus typically has single flowers that contain four petals. The double-flower phenotype of rapeseed has been a desirable trait in China because of its potential commercial value in ornamental tourism. However, few double-flowered germplasms have been documented in B. napus, and knowledge of the underlying genes is limited. Here, B. napus D376 was characterized as a double-flowered strain that presented an average of 10.92 ± 1.40 petals and other normal floral organs. F, F and BC populations were constructed by crossing D376 with a single-flowered line reciprocally. Genetic analysis revealed that the double-flower trait was a recessive trait controlled by multiple genes. To identify the key genes controlling the double-flower trait, bulk segregant analysis sequencing (BSA-seq) and RNA-seq analyses were conducted on F individual bulks with opposite extreme phenotypes. Through BSA-seq, one candidate interval was mapped at the region of chromosome C05: 14.56-16.17 Mb. GO and KEGG enrichment analyses revealed that the DEGs were significantly enriched in carbohydrate metabolic processes, notably starch and sucrose metabolism. Interestingly, five and thirty-six DEGs associated with floral development were significantly up- and down-regulated, respectively, in the double-flowered plants. A combined analysis of BSA-seq and RNA-seq data revealed that five genes were candidates associated with the double flower trait, and BnaC05.ERS2 was the most promising gene. These findings provide novel insights into the breeding of double-flowered varieties and lay a theoretical foundation for unveiling the molecular mechanisms of floral development in B. napus.
作为一种芸薹属作物，油菜通常具有包含四个花瓣的单花。油菜的重瓣花表型在中国具有潜在的观赏旅游商业价值，一直是一个理想的性状。然而，在甘蓝型油菜中很少有记录到重瓣花种质资源，并且对其潜在的基因知之甚少。在这里，甘蓝型油菜 D376 被鉴定为重瓣花品系，其平均具有 10.92±1.40 个花瓣和其他正常的花器官。通过与单瓣品系正反交，构建了 F1、F2 和 BC 群体。遗传分析表明，该重瓣花性状是由多个基因控制的隐性性状。为了鉴定控制重瓣花性状的关键基因，对具有相反极端表型的 F1 个体群体进行了 bulk segregant analysis sequencing（BSA-seq）和 RNA-seq 分析。通过 BSA-seq，在染色体 C05 上的 14.56-16.17 Mb 区域定位到一个候选区间。GO 和 KEGG 富集分析表明，DEGs 显著富集在碳水化合物代谢过程中，特别是淀粉和蔗糖代谢。有趣的是，与花发育相关的 5 个和 36 个 DEGs 分别在重瓣花植物中显著上调和下调。BSA-seq 和 RNA-seq 数据的综合分析表明，有 5 个基因是与重瓣花性状相关的候选基因，BnaC05.ERS2 是最有希望的基因。这些发现为培育重瓣花品种提供了新的见解，并为揭示油菜花发育的分子机制奠定了理论基础。
