精细定位甜瓜白粉病抗性基因Pm-M

Fine Mapping of a Powdery Mildew Resistance Gene Pm-MR112.1 in Melon

以抗白粉病甜瓜品种MR1与感白粉病新疆地方品种新密1号为亲本,构建BC_(1)P_(2)和F_(2)群体,研究白粉病菌Px1B(P.xanthii race 1B)的抗性遗传规律。以BC_(1)P_(2)与F_(2)群体为试验材料,利用BSA(Bulked segregation analysis)结合分子标记技术发掘多态性信息,并开发分子标记进行抗性基因的遗传定位。抗病基因Pm-M位于第12染色体上Indel2276和SSR12212两个标记之间,物理距离为75.54 kb(Chr.12:22765111~22840651),在该区段含有16个基因,其中12个候选基因可能与白粉病抗性相关。本研究结果为抗病基因Pm-M的图位克隆及抗病分子育种奠定了基础。

This study analyzed the genetic resistance gene against Px1B(P.xanthii race 1B)in BC_(1)P_(2) and F_(2) populations which were derived from a cross of resistant parent MR1 and susceptible parent Xinmi No.1 in melon.By taking use of the bulked segregation analysis(BSA)using molecular markers,the polymorphisms between both pools(R vs S)were revealed followed by preliminary mapping and marker saturation in fine mapping.The segregation analysis revealed a single dominant resistance gene Pm-M against powdery mildew on chromosome 12,flanked by SSR12212 and InDel 2276.The physical interval containing Pm-M was delimited to 75.54 kb(Chr.12:22765111-22840651),where 16 genes were annotated.Among them,12 genes were considered to be candidates underlying the powdery mildew resistance.Collectively,this study laid a foundation for map-based cloning of the disease resistance gene Pm-M and its use in breeding for disease resistance melon varieties.