抗白粉病基因PmCH1302的遗传分析及染色体定位

CH1302是以来源于中间偃麦草的八倍体小偃麦TAI7047为桥梁亲本选育的高抗白粉病的小麦新品系,对白粉菌多个流行小种均表现出良好抗性。为了解其抗白粉病基因来源及其在染色体上的位置,对绵阳11×CH1302的F_1、F_2及F_(2∶3)家系进行了遗传分析,推断其抗白粉病基因可能来源于中间偃麦草,暂将其命名为PmCH1302。利用i Select 90K SNP芯片对抗、感病池进行扫描,发现位于2AL染色体上的多态性位点最多,为313个,占全部多态性位点的9.79%,且集中于2AL染色体100~105 c M和150~155 cM两个区域附近。在上述位点选取SSR标记,筛选出3对与Pm CH1302连锁的分子标记,Xwmc522、Xgwm356和Xgwm526,其中Xgwm356和Xgwm526位于Pm CH1302两侧,连锁距离分别为3.1 c M和7.8 cM。利用遗传图谱以及中国春缺体、双端体将PmCH1302定位于小麦2AL染色体上。进一步与位于2AL上的Pm4、Pm50比较发现,PmCH1302可能是位于2AL上的一个新基因或等位基因。

Genetic Analysis and Chromosomal Localization of Powdery mildew resistance gene PmCH1302

CH1302,a new wheat germplasm crossing common wheat(Jintai170) and wheat-Thinopyrum intermedium (Host)Barkworth & D.R.Dewey partial amphidiploids (TAI7047),possesses resistance to the powdery mildew.To disclose the genetic mechanisms behind this resistance,the CH1302 cultivar was crossed with a susceptible genotype Mianyang 11.Segregation of resistance race Bgt E09 was assessed in the F2 population and F2∶3 lines under controlled conditions.Results indicated that CH1302 carried a dominant gene (therefore named PmCH1302) for powdery mildew resistance.ISelect 90K SNP chip was used to develop a mapping population with F2 individuals analysis the disease resistance and susceptible pools of F2 population Mianyang1 1 × CH1302,and detected 313 polymorphism SNP locus in wheat chromosome arm 2AL.Then three codominant SSR markers around the polymorphism SNP locus,Xwmc522,Xgwm356 and Xgwm526,were identified to be linked with PmCH1302.Finally,PmCH1302 was mapped between SSR markers Xgwm356 and Xgwm526 on chromosome 2AL,and the map distance was 3.1 cM and 7.8 cM,respectively.Furthermore,our results also showed PmCH1302 may be a new powdery mildew resistance gene.