甘蓝型油菜开花期的QTL定位及候选基因鉴定

为了解析油菜开花期性状的遗传机制，利用KN DH群体在冬性、半冬性和春性环境的开花期表型和KN 高密度遗传连锁图谱，通过Wincart 2.5软件的符合区间作图法对油菜开花期性状进行QTL定位及候选基因鉴定。结果显示，共鉴定到119个开花期QTL，单个QTL解释表型变异最大是qFT-13DL16-4 （25.96%），最小的是qFT-13ZY2-1（2.48%）。利用元分析的方法将初步鉴定的QTL整合为consensus QTL，共获得26个环境稳定表达QTL，包括7个开花期主效QTL。如cqFT-A2-3、cqFT-A2-4在春性环境稳定表达，cqFT-C6-4、cqFT-C6-7、cqFT-C6-12、cqFT-C6-13在冬性和半冬性环境稳定表达, cqFT-C6-14在冬性环境稳定表达QTL。主效QTL置信区间共鉴定到15个与成花诱导相关的候选基因，如 BnaA02g12260D（RGA1）、 BnaA02g15390D（AGL12）、 BnaA02g16710D（LKP2）和BnaC06g19930D（NUA）等，这些候选基因主要涉及赤霉素、光周期、生物钟、春化作用响应和花发育等功能。可见，油菜开花期主效QTL及其候选基因的鉴定为开花期基因的精细定位和图位克隆奠定基础，也为培育早熟、高产油菜品种提供指导。

QTL Mapping and Candidate Gene Identification of Brassica napus at Flowering Stage

This study aimed to investigate the genetic mechanism of Brassica napus at flowering period using the double haploid (DH) population and KN population KN high-density genetic linkage map.The phenotype data at flowering period under winter, semi-winter and spring environments were analyzed by using composite interval mapping (CIM) of Wincart 2.5 software to locate the QTL for flowering-related traits and identify candidate genes.The results revealed a total of 119 associated with flowering stage,with qFT-13DL16-4 explaining up to 19.63% of the phenotypic variation (PV) and qFT-13ZY2-1 exhibiting the minimum PV (2.48%).Furthermore, these QTLs were integrated into a consensus QTL by meta-analysis, resulting in the identification of 26 environment-stable expression QTLs, including seven major QTLs.For example, cqFT-A2-3 and cqFT-A2-4 were stably expressed under the spring ecological environment, cqFT-C6-4, cqFT-C6-7, cqFT-C6-12, and cqFT-C6-13 were stably expressed in winter and semi-winter ecological regions, and cqFT-C6-14 was stably expressed in the winter ecological region.In conclusion, this study provides a foundation for fine mapping and map-based cloning of causal genes and offers guidance for the cultivation of new early maturing and high-yield rapeseed varieties in the future.Fifteen candidate genes involved in flowering regulation were identified within QTL confidence intervals,including BnaA02g12260D (RGA1), BnaA02g15390D (AGL12), BnaA02g16710D (LKP2) and BnaC06g19930D (NUA), and these candidate genes are involved in the regulatory pathways, such as gibberellin, photoperiod, circadian clock, vernalization response and flower development.In conclusion,this study lays a foundation for fine mapping and map-based cloning of causal genes and offers guidance for the cultivation of new early maturing and high-yield rapeseed varieties in the future.