粗山羊草抗病基因向普通小麦转移及抗病基因标记的研究

Transfer of resistant genes from Aegilops tauschii L. to Triticum aestivum L. and their mapping by SSR

为将粗山羊草(Aegilops tauschii)抗白粉病基因转移到普通小麦中,用普通小麦与粗山羊草配制杂交组合,利用SSR标记技术结合BC1F2分离群体对目的基因进行了遗传作图。结果显示,普通小麦与粗山羊草杂交不能正常结实,进行幼胚拯救可获得组培苗,成胚率达到9.22%;矮败与Y215杂种F1自交不育,与普通小麦回交可正常结实,但BC1自交结实率极低。进一步对矮败×Y215杂种后代进行抗病鉴定和遗传分析,粗山羊草Y215含有一对显性抗白粉病基因,并分别在杂种后代BC2F1和BC1F2中获得了细胞学稳定且与供体亲本一致的抗白粉病植株;应用SSR标记和分离群组分离法,分析与其连锁的引物位置,将其定位在3DS染色体上,暂时命名为PmY215。说明来自粗山羊草Y215的抗病基因已通过遗传重组导入普通小麦中,分析PmY215基因所在染色体的位置和抗病性特征,认为PmY215是一个新的显性抗小麦白粉病基因,并可用于分子标记辅助选择。本研究发现的粗山羊草Y215的抗小麦白粉病基因PmY215是一个新的基因。

In order to transfer powdery mildew resistant genes to common wheat, Aegilops tauschfi （2n = 14） accessions （as male） were crossed with T, aestivum （2n =42,AABBDD） cultivars/lines, and SSR markers were used to identify genetically linked markers to the target gene. We found that the immature embryos of the crosses T. aestivum x Ae. tauschii must be rescued because of shriveling of endosperm in hybrid seeds, and the percentage of embryos obtained was 9.22% on the average. The hybrid of aibai/Y215 F1 plants were sterile, and hybrid seeds could be obtained through backcrossing with T. aestivum, but seed set of the intercross in BC1 progenies was very low. The Ae. tauschii Y215 carried a dominant powdery mildew gene and the derivative lines of BC2F1 and BCF2 inherited normal chromosomes and were resistant to powdery mildew. Using microsatellite markers and bulk segregation analysis, the resistant gene, PmY215 was located on chromosome 3DS,temporarily designated as PmY215. This indicated that the powdery mildew resistant genes originating from Ae. tauschii Y215 accessions were successfully transferred to hexaploid wheat. Based on the PmY2]5 location on the chromosome and the resistance pattern of the gene, we propose that PmY215 is a novel dominant powdery mildew resistant gene, which may be used for marker-assisted selection.