Fine Mapping And Candidate Gene Identification For Stripe Rust-Resistance Gene YrJ22 In Common Wheat

Wheat stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most damaging diseases for wheat production.The using of resistance varieties is the most economical and effective approach for controlling this disease.Discovery and application of new disease-resistant genes are the key to gene aggregation and distribution.YrJ22 is a dominant stripe rust resistance gene with high resistance for CYR32 located at the end of 2AL that was found in Jimai22.In current study,To finely map YrJ22 by BSR-Seq and RNA-seq approach,5000 F2 plants derived from the cross of Jimai22/Avocet S were used for phenotyping and genetic analysis by inoculating with CYR32.To screen candidate gene and develop molecular markers for wheat stripe rust resistance breeding,1200 EMS mutants of Jimai22 were scan for MutMap.(1)A total of 1720 resistant plants and 553 susceptible plants were obtained in F2 population,and the separation ratio fited 3:1(χ2=0.46,P1df>0.05).Resistant and susceptible bulks selected from F2 population were screened by RNA-Seq,and a region closely related to the traits was located at 13.91 Mb interval on chromosome 2A.(2)990 resistance and 32 susceptible materials were identified in Jimai22 EMS mutants.A region closely related to the trait on chromosome 2A were detected using sequencing analysis by Mutmap,with a 37.61Mb physical interval.(3)Based on the genome information of linked SSR markers in former study,combined with RNA-Seq and MutMap analysis,YrJ22 was located on a 4.68 Mb region on 2A,in which annotated 70 genes.By screening the 70 genes for gene function annotation,10 genes related to resistance were obtained and used as candidate genes for YrJ22.