甘蓝型油菜叶片花青素及叶绿素含量的QTL定位

QTL Mapping of Leaf Anthocyanin and Chlorophyll Content in Brassica napus

【目的】花青素和叶绿素是植物体显色和光合作用的两类重要色素,为定位甘蓝型油菜叶片花青素和叶绿素含量的QTL,进而发掘和筛选调控该性状的候选基因,为甘蓝型油菜叶片花青素和叶绿素含量的遗传改良提供支撑。【方法】利用甘蓝型紫叶油菜10-Zi006和绿叶油菜10-4438为亲本构建BC_(1)分离群体,基于该群体构建的连锁遗传图谱,利用Windows QTL Cartographer 2.5软件,采用复合区间作图(Composite interval mapping,CIM)法进行QTL定位。【结果】甘蓝型油菜叶片花青素含量在BC_(1)群体呈连续偏态分布、叶绿素含量呈连续正态分布;在6个连锁群上检测到14个叶片花青素含量的QTL,分别定位在chrA03、chrA05、chrC02、chrC03、chrC04、chrC07、chrAnn;andom、chrAnn;andom、chrC04;andom染色体的相关区域,贡献率为9.17%~19.13%;在7个连锁群上共检测到8个叶片叶绿素含量的QTL,分别定位在甘蓝型油菜chrA03、chrA06、chrA07、chrA08、chrC01、chrC03、chrC06、chrC07、chrAnn;andom、chrCnn;andom、chrC03;andom染色体相关区域,贡献率为4.45%~13.07%。将定位到的QTL整合到甘蓝型油菜参考基因组上并功能注释发现一些转录因子、细胞色素P450蛋白及UGT-糖基转移蛋白等可能参与调控叶片花青素的合成,PORB、HCF、NYC等基因可能与叶绿素含量相关。【结论】上述染色体相关区域内可能存在调控甘蓝型油菜叶片花青素和叶绿素合成的相关基因,筛选这些候选基因,进一步开展基因功能验证,明确该性状遗传机制的基础。

【Objective】The leaf anthocyanin and chlorophyll are two important pigments related to coloration and photosynthesis in plant.The QTLs of leaf anthocyanin and chlorophyll content in Brassica napus are mapped to further explore and screen the candidate genes regulating their characters and provide the technical support for genetic improvement of leaf anthocyanin and chlorophyll content in Brassica napus.【Method】The BC_(1)segregation population is constructed from 10-Zi006 with purple leaves and 10-4438 with green leaves.The QTLs of BC_(1)population is mapped by using Windows QTL Cartographer 2.5 and Composite interval mapping method(CIM)based on the genetic linkage map structured from BC_(1)population.【Result】The anthocyanin content showed a continuous skewed distribution but leaf chlorophyll content shows a continuous normal distribution in BC_(1)population.14 QTLs of leaf anthocyanin content detected in six linkage groups were mapped in relative regions of chrA03,chrA05,chrC02,chrC03,chrC04,chrC07,chrAnn;andom,chrAnn;andom and chrC04_andom and the contribution rate was 9.17%-19.13%.8 QTLs of leaf chlorophyll content detected in seven linkage groups were mapped in relative regions of chrA03,chrA06,chrA07,chrA08,chrC01,chrC03,chrC06,chrC07,chrAnn;andom,chrCnn;andom and chrC03;andom and the contribution rate was 4.45%-13.07%.QTLs mapping to the reference genome of B.napus and genes function annotation showed that some transcription factors,cytochrome P450 protein and UDP-glucosyl transfer protein may regulate and control the synthesis of anthocyanin and PORB,HCF,NYC etc.may be associated with chlorophyll content in B.napus.【Conclusion】There may be the relative genes regulating anthocyanin and chlorophyll synthesis in the relevant regions of the above-mentioned chromosomes in B.napus.Screening these candidate genes is the basis to further develop gene function identification and clarify genetic mechanism of anthocyanin and chlorophyll synthesis in B.napus.