Construction Of Genetic Map Of Wheat Cypa35-3 Powdery Mildew Resistance Gene And Xinong 529 Stripe Rust Resistance Gene

Powdery mildew and stripe rust pose a serious threat to the yield and quality of wheat.It is of great significance for the control of wheat powdery mildew and stripe rust to continuously explore new resistance genes and broaden the genetic resources of resistance genes.In this study,the wheat germplasm with high resistance to wheat powdery mildew,Persian wheat Cypa35-3,and the wheat variety Xinong 529 with high resistance to stripe rust were studied respectively.The main contents are as follows:1.Mapping of Adult Powdery Mildew Resistance Genes of Wheat idioplasm Cypa35-3Persian wheat Cypa35-3 from the Soviet Union showed high resistance to powdery mildew at adult stage to the dominant race of powdery mildew in Guanzhong area of Shaanxi Province.In order to study the inheritance of powdery mildew resistance gene and clarify the chromosome location of powdery mildew resistance gene,Cypa35-3 was crossed with flavescens（cultivated emgrain wheat）with high powdery mildew susceptibility,and the parents and their hybrids F₁,F₂ and F_2∶3 populations were evaluated and genetic analysis in the adult stage.The phenotypic identification results showed that F1 showed high resistance,and the ratio of F₂ powdery mildew susceptibility was close to 3:1.The resistance ratio of F_2∶3 was close to 1:2:1,indicates that the powdery mildew resistance of Persian wheat Cypa35-3is controlled by a pair of dominant gene,temporarily named Pm Cypa35-3.A total of 601 pairs of SSR markers were distributed on 14 pairs of chromosomes of chromosome A and B,and the polymorphism markers of F₂ population of Cypa35-3 were screened by separation population grouping analysis（BSA）.Four pairs of SSR markers（Xbarc81,Xcfd48,Xbarc61,Xbarc302）on chromosome 1B were linked to the powdery mildew resistance gene Pm Cypa35-3.Xbarc81 and Xcfd48 were located on both sides of Pm Cypa35-3,with genetic distances of 25.2 c M and 8.6 c M,respectively.Therefore,the adult stage powdery mildew resistance gene Pm Cypa35-3 was preliminarily localized on chromosome 1B.By comparing the gene source and marker location of the formally named powdery mildew resistance genes on chromosome 1B（Pm8,Pm28,Pm32 and Pm39）and Persian wheat（Pm4b and Pm33）,Pm Cypa35-3 was found to be different from them.Preliminary speculation that Pm Cypa35-3may be a new wheat powdery mildew resistance gene during the adult stage,which can provide a new resistance source for wheat varieties resistant to powdery mildew.2.Mapping of stripe rust resistance gene of wheat variety Xinong 529.Xinong 529 has the characteristics of strong tillering ability,high quality and strong gluten,and it shows high resistance to wheat stripe rust.Our laboratory has preliminarily located the stripe rust resistance gene of Xinong 529 on chromosome 1B in the early stage.In order to better utilize the stripe rust resistance gene of Xinong 529,the genetic rule of stripe rust resistance gene in the new genetic background population was studied and other good genes in Xinong 529 were extracted.A total of 445 F₂ generation isolated populations were constructed by crossing Xinong 529 with Xinong 979.Physiological subspecies CYR31 were used for stripe rust resistance evaluation and genetic analysis at different stage and and genetic analysis was carried out.Finally,resistance and sensitivity gene pools were constructed by BSA method,and specific molecular markers were designed and developed by SSR molecular marker screening and SNP analysis on wheat 660K chip.Molecular marker linkage analysis was performed on F₂ generation population.The results showed that stripe rust resistance of Xinong 529 was controlled by a pair of dominant gene,tentatively named Yr XN529.Two pairs of SSR markers located on chromosome 1B were linked to Yr XN529,Xwmc694 and Xcfd48,respectively.In addition,the SNP analysis results of 660K chip showed that the SNP differential loci of Xinong 529 were mainly concentrated in the 300 Mb to 330 Mb and 570Mb to 600 Mb of chromosome 1B.Based on the results,50 pairs of SNP primers were designed and synthesized to screen polymorphic molecular markers for parents,resistance/susceptibility gene pool and F₂ generation mapping population.Finally,four SNP_S（SNP01,SNP04,SNP23,SNP43）were linked to Yr XN529.The molecular markers located on both sides of Yr XN529were SNP01 and Xwmc694,with genetic distances of 11.5 c M and 27.6 c M,respectively.By comparing with the formally named stripe rust resistance gene on chromosome 1B,it was speculated that Yr XN529 may be a new stripe rust resistance gene from Thinopyrum elongata.At the same time,the plant growth and disease resistance related genes were excavated in the enrichment area of the two SNPs of Yr XN529,and 50 candidate genes were finally screened,including 31 disease resistance related genes.These disease resistance related genes laid the foundation for the subsequent cloning and functional verification of Yr XN529 gene.At the same time,Yr XN529 was hybridized with wheat varieties promoted and utilized in production,providing a guarantee for enriching the wheat disease resistance gene resource pool.