结球甘蓝抗霜霉病基因连锁的SCAR标记开发

Development of SCAR Molecular Marker Linked to Downy Mildew Resistance Gene in Cabbage

结球甘蓝霜霉病是由十字花科寄生霜霉菌引发的严重病害。本研究利用高代自交系‘R103’抗病亲本和‘S101’感病亲本及其F2分离群体,于霜霉病病发高峰期田间自然诱发抗性鉴定,由单基因显性控制。运用AFLP分子标记技术,结合BSA法,对双亲和2对抗、感基因池的筛选和验证,获得2个与结球甘蓝抗霜霉病基因相关的AFLP标记。204 bp BoRAAC/CAC标记转化为SCAR标记,发现在抗病亲本和抗病池中与感病亲本和感病池中条带只存在量上的差异,在抗性选择起中只能起辅助作用;191 bp BoRAAG/CTC标记(EU-635443.1),转化为SCAR标记,仅在抗病亲本和2个抗病池中获得目的条带,经F2群体单株验证后,与抗性位点的遗传距离为5.7cM。利用BoRAAG/CTC113标记对F1和BC1群体与多年苗期霜霉病抗性鉴定的20份结球甘蓝种质资源进行验证和筛选,该标记与品种(系)的霜霉病抗性吻合率达到95%,初步表明该标记可应用于早期结球甘蓝抗霜霉病抗性辅助选择。

Downy mildew caused by the oomycete Hyaloperonospora parasitica Constant. （Pers. Ex Fr.） is a serious threat to Brassicaceae family. In this study, the resistance was conferred by a single dominant gene of F2 young adults, gotten from high inbred lines ＇R103＇ resistant parent and ＇S 101＇ susceptible parent, on the disease peak stage in field. AFLP technology was applied to identify the markers linked to downy mildew resistant locus based on BSA method. Two resistant AFLP markers were obtained from the parents and two pairs of pools, which constructed from F2 plants. The 204 bp marker BoRaa,acnc, which has been converted to SCAR marker, indicated the quantitive difference, so it is only for resistance selection diminutively. Whereas, the 191 bp marker BoRaaccc （Accessment number： EU635443.1）, which has been converted to the SCAR marker, was only obtained from the resistant parent and pools, and the genetic distance between the downy mildew resistant gene is 5.7 cM verified by F2 plants. In addition, the F~ and BC, population had verified the accuracy of the SCAR marker BoRaacccrcm, and 20 materials also had verified its accuracy, the reistance consistency was 95%. These results demonstrated that the BORAAGCIClI3 provided a basis SCAR marker for resistance identified and marker assisted breeding in headed cabbage.