小偃麦衍生系CH984抗白粉病基因定位

Mapping of Powdery Mildew Resistance Gene in a Tritipyrum-derived Line CH984

小麦种质CH984为八倍体小偃麦TAI7047与小麦品种‘晋太170’杂交后代衍生而来的高代选系,在成株期对中国白粉病菌株E09表现免疫,抗病表现与TAI7047相似。将CH984分别与小麦感病材料TC29和SY95-71配置组合,获得CH984/TC29 RIL群体和CH984/SY95-71 F2群体。利用E09对2个遗传群体进行苗期接种鉴定和遗传分析,证实CH984携带1个主效抗白粉病基因,暂命名为PmCH984。采用分离群体分组分析法对CH984/TC29 RIL群体家系的抗感池扫描小麦90K芯片,结果显示多态性SNP标记主要位于小麦2D染色体长臂400~450 Mb区段。在目标区段内每隔5 Mb开发1个SSR标记,并结合2DL染色体上的公共SSR标记和NRM标记扩增CH984/TC29 RIL群体,最终利用8个SSR标记将PmCH984定位在1个40 Mb的物理区间内,与侧翼连锁标记Xcfd2和SSR3的遗传距离分别为2.5和0.1 cM。位点分析表明,PmCH984是一个新的抗白粉病基因。

Wheat germplasm CH984 is a high-ge neration selection line derived from the hybrid offspring of octoploid Tritipyrum TAI7047 and variety ’Jintai170’. It is immune to the domestic Blumeria graminis f. sp. tritici(Bgt) strain E09 at adult stage, which is similar to TAI7047. CH984 was crossed with wheat susceptible materials TC29 and SY95-71 respectively to obtain CH984/TC29 RIL population and CH984/SY95-71 F2population. Confirmed by inoculation identification and genetic analysis of the two populations at seedling stage using Bgt E09,CH984 carried a major powdery mildew resistance gene, tentatively named PmCH984. Bulked segregant analysis combining wheat 90K microarray were used to scan the resistant bulk and susceptible bulk of CH984/TC29 RILs,and the results showed that polymorphic SNP markers were mainly located in the 400~450 Mb segment of long arm of wheat chromosome 2D. One SSR marker per 5 Mb within the target segment was developed, and these developed markers along with the public SSR markers and NRM markers on chromosome 2DL were used to amplify the CH984/TC29 RIL population. Finally, 8 SSR markers were mapped with PmCH984 in a 40 Mb physical interval, and the genetic distances of PmCH984 from flanking markers Xcfd2 and SSR3 were 2.5 and 0.1 cM, respectively. Locus analysis showed that PmCH984 is a new powdery mildew resistance gene.