Preliminary Mapping of Leaf Rust Resistance Genes in Wheat Line Tian 05156-1-1-2-1-2-1

Wang Xinrui; Bai Bin; Wang Jinshuo; Gao Pu; Wang Xinhai; Liu Yiran; Wang Hanbing; Li Zaifeng; Dong Haijiao; Zhang Peipei

doi:10.15933/j.cnki.1004-3268.2026.08.003

Abstract：According to the previous identification result of resistance to leaf rust at seedling stage,the wheat line Tian 05156-1-1-2-1-2-1 currently exhibited resistance to most physiological races of leaf rust in China.To identify the leaf rust resistance genes carried by this line,Tian 05156-1-1-2-1-2-1 was crossed with the susceptible wheat variety Zhengzhou 5389 to obtain F1 and F2 generations.The leaf rust resistance of the parents and their hybrids was evaluated using THSN,five resistant and five susceptible individual plants were sent to a company for 16K SNP chip analysis,single nucleotide polymorphism(SNP)loci that exhibited polymorphism between the resistant and susceptible small populations were identified.Based on the chromosomes where the differential SNPs were located,KASP markers were designed,KASP markers and known SSR markers were used to detect the parents and F2 populations,and the genotypes of the population were obtained.The leaf rust resistance genes in Tian 05156-1-1-2-1-2-1 were mapped by combining phenotype and genotype data.Candidate genes within the mapping region were identified based on the Chinese Spring reference genome(IWGSC RefSeq V2.1)sequence.The results showed that Tian 05156-1-1-2-1-2-1 exhibited high resistance[infection type(IT)=1],while Zhengzhou 5389 demonstrated high susceptibility(IT=4)at seedling stage.All 10 F1 plants displayed resistance(IT≤2).Among the 200 F2 individual plants,146 plants were resistant(IT≤2),and 53 plants were susceptible(IT≥3).Chi-square test revealed that the number of resistant and susceptible single plants conformed to 3∶1 segregation ratio(χ²3∶1=0.284,p>0.05).It was inferred that Tian 05156-1-1-2-1-2-1 might contain a dominant major gene conferring resistance to leaf rust,and it was designated as LrGW.By using a 16K SNP liquid-phase chip to detect resistant and susceptible bulks,281 SNPs located on chromosome 1B showed no recombination events in the bulks,indicating that LrGW was likely located on chromosome 1B.Thirty-one KASP markers were developed based on Chinese Spring reference genome and different SNP loci,and five markers showed good polymorphisms between resistant and susceptible parents,including Zbh1B27,Zbh1B28,Zbh1B30,Zbh1B43,and Zbh1B44.In addition,one known SSR Xbarc8 showed good polymorphism between two parents.Xbarc8 and five KASP markers were used to test the F2 population,and LrGW was mapped to chromosome 1B between Zbh1B28 and Zbh1B30,with the genetic distances of 0.4 cM and 1.1 cM,respectively,corresponding to the physical interval of 285.7-306.2 Mb in the Chinese Spring reference genome.Analysis of annotated genes within the candidate regions revealed that four kinase genes,including TraesCS1B02G164400,TraesCS1B02G167400,TraesCS1B02G167500,and TraesCS1B02G167700,were potential candidates for LrGW.