Marker Encryption And Marker Assisted Polymerization Of Powdery Mildew Resistance Gene Pm37 In Wheat

Wheat powdery mildew is a leaf disease caused by Blumeria graminis f.sp.tritici(BGT).Wheat infected with powdery mildew will generally cause 10-20% yield loss,and it may be more than 50% in severe cases.In recent ten years,the incidence area of Wheat Powdery Mildew in China is more than 100 million mu every year,which poses a serious threat to the food safety in China.In the face of the epidemic situation of wheat powdery mildew,it is mainly controlled by applying chemicals in the fields and planting resistant varieties.In contrast,breeding resistant varieties is undoubtedly the most effective and environmentally friendly strategy.However,with the continuous variation of wheat powdery mildew virus strains,the resistance genes of many existing varieties gradually lost their resistance to powdery mildew.It is urgent to introduce more broad-spectrum powdery mildew resistance genes to balance the distribution of resistance genes and improve the ability of resistant varieties to resist powdery mildew variation.Pm37 from timofivi a genome was transferred to wheat background and located on7 AL chromosome.In order to promote the breeding and utilization of Pm37,the molecular marker density of the mapping region of Pm37 was increased,and the marker assisted polymerization of Pm37 was used.The details are as follows:(1)Using bulked segregant RNA SEQ(BSR SEQ),the SNP associated with Pm37 was found,and molecular markers were designed YT001,YT004,YT005,YT007,YT014,YT018,YT021,YT023,YT035,YT063,K-085 and K-101.It was closely linked with Pm37,which further increased the molecular marker density of Pm37 localization region and located Pm37 in the 0.5 c M region.(2)The results showed that Pm37 was immune to fifty strains,which indicated that Pm37 was a broad-spectrum powdery mildew resistance gene.Furthermore,we comprehensively evaluated the agronomic and yield characters of Pm37 vector material,and found that Pm37 vector material had excellent agronomic and yield characters except broad-spectrum resistance.Therefore,we think that Pm37 is a new powdery mildew resistance gene with important breeding value.(3)Using 12 common PCR markers and 2 KASP markers,29 susceptible cultivars were detected.It was found that these markers could detect Pm37 in more than 50%cultivars.The markers YT001,YT004,YT005,YT007,YT014,YT018,YT021,YT023,YT035,YT063,K-085 and K-101 were polymorphic in all tested cultivars,which was regarded as the wide adaptability of Pm37.Therefore,these markers can be used in marker assisted selection breeding of Pm37.(4)In order to combine Pm37 with other broad-spectrum powdery mildew resistance genes for marker assisted breeding,we further developed the functional kasp of three broad-spectrum powdery mildew resistance genes Pm12,Pm21 and Pm V.Although Pm12,Pm21 and Pm V are lineal homologous genes,the functional kasp markers developed by us can not only distinguish these three genes,but also distinguish them from other known powdery mildew resistance genes,which are useful breeding markers with important breeding value.(5)In order to realize the polymerization of Pm37 and these genes,we have constructed the progeny population of Pm37 and these three gene vector materials.At present,we are using the breeding markers of Pm37,Pm21,Pm12 and Pm V to select the materials that polymerize multiple disease resistance genes for molecular marker assisted polymerization breeding.