小麦抗白粉病基因Pm2的SSR标记筛选

为筛选与小麦抗白粉病基因Pm2紧密连锁的分子标记,将感病品种Chancellor与Pm2的近等基因系杂交,获得F1、F2分离群体,采用分离群体分组法对Pm2进行了微卫星(microsatellite,又称simple sequence repeats,SSR)标记分析.结果表明,定位于小麦5D染色体上的71对SSR引物中有12对引物能在Pm2的近等基因系、Chancellor间稳定地揭示出多态性差异,7对引物Xcfd189、Xcfd29、Xcfd8、Xcfd102、Xcfd7、Xcfd57和Xgwm190分别能在抗病、感病池间和F2分离群体的抗病、感病单株间稳定地扩增出特异性产物.7对引物所扩增的特异谱带分别为:Xcfd189360、Xcfd29190、Xcfd8160、Xcfd102250、Xcfd7200、Xcfd57245和Xgwm190210,它们与Pm2基因间的遗传距离分别为0、1.5、2.3、5.4、10.2、31.5和54.3 cM,其中标记Xcfd189360与Pm2共分离,标记Xcfd29190、Xcfd8160和Xcfd102250与Pm2紧密连锁,可用于Pm2的标记辅助选择.

Screening for SSR markers linked to wheat powdery mildew resistance gene Pm2

To detect molecular markers linked to wheat powdery mildew resistance gene Pm2, microsatellite (simple sequence repeats, SSR) markers and bulked segregant analysis (BSA) method were used in the F₂ segregation population derived from the F₁ of between common wheat susceptible cultivar Chancellor and Pm2 near-isogonics line (NIL). The polymorphisms were revealed by 12 from 71 pairs SSR primers originally assigned to chromosome 5D of wheat between NIL of Pm2 and Chancellor. The polymorphic bands were found by 7 of these 12 SSR primers between the resistant and susceptible DNA pools, and the resistant and susceptible plants of the F₂ population, respectively. These specific DNA bands were designated as Xcfd189₃₆₀, Xcfd29₁₉₀, Xcfd8₁₆₀, Xcfd102₂₅₀, Xcfd7₂₀₀, Xcfd57₂₄₅ and Xgwm190₂₁₀, respectively. The genetic distance between these marks and Pm2 was 0, 1.5, 2.3, 5.4, 10.2, 31.5 and 54.3 cM, respectively. On the genetic linkage map of Pm2, Xcfd189₃₆₀ was shown to co-segregate with the Pm2 gene, and markers Xcfd29₁₉₀, Xcfd8₁₆₀ and Xcfd102₂₅₀ were closely linked to it. These markers can be used as the molecular assisted selection (MAS) for Pm2.