油菜开花期QTL定位和候选基因分析

QTL mapping and candidate genes analysis for flowering time in rapeseed (Brassica napus L.)

为辅助选育早熟油菜品种、克隆油菜开花期基因及开发花期分子标记,以已测序的油菜品种中双11(Z)和重测序的油菜品系No.73290(N)为亲本构建的含184个单株的BnaZNF2群体为材料,通过分析该群体的基因型数据和F2:3家系连续三年(2010-2012)在武汉的表型数据,对开花期QTL进行检测和整合,定位到分布在11个连锁群上的14个开花期QTL。其中只有5个QTL能在3年中重复检测到,分别是qDtF.A2-1、qDtF.A6-2、qDtF.C2-1、qDtF.C2-2和qDtF.C3-1,贡献率在7.1%~21.1%之间。通过查阅文献和在拟南芥、水稻等作物网站上搜索,搜集到442个与植物开花期有关的基因。基于油菜基因组物理图谱,通过生物信息学分析,在本研究定位的QTL区间上筛选到54个可能的候选基因,可以用于开花期基因的克隆。在5个主要QTL区间内分别定位到8、5、4、2和4个候选基因,其中有15个在双亲中存在序列差异,可以开发开花期的功能标记用于分子标记辅助选择育种。

For molecular marker-assisted breeding on early-mature rapeseed,BnaZNF2 population containing 184 individuals was constructed using the sequenced rapeseed cultivar ZS11 and re-sequencing rapeseed line No.73290 as parents.Flowering time QTLs were detected and integrated using both genotype and phenotype data of F2:3 family in Wuhan for 3 years(2010-2012).14 QTLs were mapped for flowering time distributed on 11 linkage groups.5 QTLs were detected repeatedly in 3 years,including qDtF.A2-1,qDtF.A6-2,qDtF.C2-1,qDtF.C2-2 and qDtF.C3-1.Their contributions were between 7.1%and 21.1%.Through literature reviewing and searching on web sites on Arabidopsis and rice,442 genes related to plant flowering time were collected.Based on the physical map of rapeseed genome,54 putative candidate genes were envolved in the QTL intervals by bioinformatics analysis.2 to 8 candidate genes were mapped respectively on 5 major QTL intervals,15 of which had sequence differences be tween parents.The 15 putative candidate genes for flowering time could be developed into functional markers for molecular marker-assisted selection and plant breeding.