甘蓝型油菜桔红花色基因Bnpc2紧密连锁标记的开发及其应用

Developing of Molecular Markers Closely-linked with Orange Petal Color Gene Bnpc2 in Brassica napus L.and Application

培育出带有标记性状的甘蓝型油菜桔红花色恢复系,在杂交种制种过程中可以起到指示作用来去除恢复系杂株,从而提高杂交种纯度和产量。开发与甘蓝型油菜桔红花色基因紧密连锁的分子标记,有利于快速培育出甘蓝型油菜桔红花色恢复系。前期研究表明,甘蓝型油菜桔红花色性状受Bnpc1和Bnpc2两对隐性核基因控制,并将Bnpc1定位到151 kb的区间范围内。本研究以BC3分离群体(即与轮回亲本回交三代且经过等位性检验仅在Bnpc2位点处发生分离的群体)为材料,利用AFLP和SSR标记技术对基因Bnpc2进行了基因定位,获得18个与Bnpc2紧密连锁的分子标记,其中两侧最近的标记分别为4个共分离的SSR标记(BnA09-19,BnA09-22,BnA09-24,BnA09-25)和P11/MC02,它们与目的基因的遗传距离分别为0.12和1.74 cM,标记间的遗传距离为1.86 c M,因而甘蓝型油菜桔红花色基因Bnpc2被锁定在1.86 cM的区间范围内。同时,筛选得到1个与基因Bnpc2紧密连锁的共显性标记BnA09-22。利用与基因Bnpc1和Bnpc2紧密连锁的共显性标记进行分子标记辅助育种,选育出1个甘蓝型油菜桔红花色恢复品系4750R,并进行了三系配套,审定了甘蓝型油菜杂交种‘青杂15号’。

The orange petal color(OPC)B.napus restorer lines were bred,the orange petal color would be used as marked character to remove plants of restorer line when increasing the hybrid variety seeds.For breeding OPC B.napus restorer lines quickly,it is necessary to develop molecular markers closely linked with OPC gene in Brassica napus L..The previous study isolated and identified two genes(Bnpc1 and Bnpc2)that control the OPC trait in B.napus,and mapped Bnpc1 to a 151 kb region.The study report the fine-mapping of Bnpc2.Crossing,allelism testing,and repeated full-sib mating were used to generate BC3,a near isogenic line(NIL)population that segregated on the Bnpc2 locus.10 AFLP and 8 SSR markers closely linked with Bnpc 2 were developed and the genetic linkage maps of Bnpc2 were constructed for the NIL population.The closest flanking markers located on either side of Bnpc2 were four co-segregated SSR markers(BnA09-19,BnA09-22,BnA09-24,BnA09-25)and P11/MC02,which were 0.12 and 1.74 cM away from the target gene,respectively.The Bnpc2 gene was eventually delimited to a region of 1.86 cM.And the co-dominant marker closely linked with Bnpc2,BnA09-22 was identified.Then,the co-dominant markers closely linked with Bnpc1 and Bnpc2 respectively,were used for marker-assisted selection to breed B.napus OPC restorer lines.Finally,a B.napus OPC restorer line 4750 R with good agronomic characters was bred.Three lines,including sterile line,restorer line and maintainer line,were matched.A new B.napus hybrid cultivar’Qingza NO.5’was registered.