Maeker Development And Resistance Spectrum Analysis Of A Dominant Powdery Mildew Resistance Gene PmD29 From Common Wheat

Powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is one of the three most devastating wheat diseases and severely affects the security of wheat production.Utilization of new disease-resistant cultivars is the most cost-efficient,effective and environment friendly approach to control this disease.Since the large amount number and rapid variation of the Bgt isolates,constantly exploring and utilizing new powdery mildew resistance genes is a long-term task for wheat breeders.PmD29 is a dominant powdery mildew resistance gene identified in common wheat germplasm D29 in our previous study.It has been mapped to a 6.0 cM interval flanked by Xhbg327 and Xgdm93 on chromosome 2AL.In order to saturate the genetic map of PmD29,several strategies were adopted to develop new markers,including obtaining marker information from Chinese Spring genetic map and published articles,getting genome sequence information of common wheat and its ancestor species and establishing the micro-colinearity relationship among wheat,brachypodium and rice and so on.Finally,PmD29 was delimited to 1.2 cM interval,flanked by Xwgrc865 and Xwgrc883 with 0.8 cM and 0.4 cM,respectively.In addition,resistance spectrum analysis was performed by evaluating the responses of Yangmai 158 NILs harbored PmD29,Pm4a,Pm4b and Pm4c after inoculation with 20 isolates,respectively.The result indicated that the resistance spectrum of PmD29 is different from Pm4a,Pm4b and Pm4c.Therefore,PmD29 is a new powdery mildew resistance allele of Pm4 locus.