利用微卫星标记定位一个新的小麦抗白粉病基因

小麦农家品种ZB90是一个广谱抗白粉病材料.苗期和成株期鉴定表明,其白粉病抗性由显性单基因控制.从位于不同染色体上的53对微卫星引物中筛选出3对引物(Wms382、Wms311和Wms312),对144株F2分离群体进行抗病连锁性分析.另外,与Pm4a共分离的STS标记STS-470也被用于基因定位.这4个标记和抗病基因在染色体上的顺序为:基因位点-Xgwm382-Xgwm311-STS-470-Xgwm312,它们之间的遗传距离分别为2.9、4.5、23.1和49.6 cM,与小麦染色体2AL上已构建的微卫星图谱顺序一致.根据材料来源和抗病基因的染色体定位结果,确定该基因为一个新的小麦抗白粉病基因,并命名为PmZB90.文中还讨论了PmZB90和其他位于染色体2AL上的基因之间的关系.

Chromosomal Location of a New Powdery Mildew Resistance Gene in Broad-spectrum Resistant Wheat Using Microsatellite Markers

Chinese native wheat ZB90 has been an effective broad-spectrum powdery mildew resistance variety.Genetic analysis showed that the resistance was controlled by a single dominant gene at the seedling and adult stage.Among the 53 pairs of microsatellite primers located on different chromosome,three polymorphic microsatellite markers Xgwm382,Xgwm311 and Xgwm312 on the long arm of chromosome 2A were screen in 144 F2 segregating populations for the powdery mildew resistance gene in ZB90.Sequence tagged site(STS) STS-470 cosegregated with Pm4a were also used for gene location.The orders of the four markers and the resistance gene locus were: gene locus-Xgwm382-Xgwm311-STS-470-Xgwm312 with genetic distances of 2.9 cM,4.5 cM,23.1 cM,49.6 cM for the four intervals,and agreed well with the established microsatellite map of chromosome 2AL.It was concluded that the resistance gene was located on chromosome 2AL.Based on the origin and chromosomal location of this gene,it is suggested that the resistance gene derived from a novel powdery mildew resistance gene and is temporarily designated as PmZB90.The relation between this gene and other powdery mildew resistance genes located on chromosome 2AL were discussed.