Detection and molecular cytological identification of disease resistance genes of new wheat variety Yunmai 112

【Objective】To conduct disease resistance gene detection and molecular cytogenetic identification of the new wheat variety Yunmai 112, clarify its resistance gene composition against stripe rust and powdery mildew, which could provide theoretical basis for promotion of the variety and utilization of the resistance genes. 【Method】Using the new wheat variety Yunmai 112 as the test material, this study combined seedling-stage inoculations with stripe rust or powdery mildew races（CYR23, CYR29, CYR31, CYR32, CYR33, CYR34 and E26） with adult-plant stage inoculations using mixed races for resistance evaluation of Yunmai 112 against stripe rust and powdery mildew, employing Nannong 0686 and Mingxian 169 as susceptible controls. Infection types were recorded as 0-9 grades. Molecular marker technology was utilized to detect powdery mildew and stripe rust resistance genes in Yunmai 112 through the application of either closely linked or gene-specific molecular markers targeting powdery mildew and stripe rust resistance genes. Additionally, genomic in situ hybridization（GISH） was performed to dissect chromosomal composition, complemented by fluorescence in situ hybridization（FISH） to precisely locate alien chromosome segments and determine their genetic origin. 【Result】Resistance evaluation revealed that Yunmai 112 exhibited immunity against 5 stripe rust pathogen races（CYR23, CYR31, CYR32, CYR33, CYR34） and high resistance to stripe rust pathogen race CYR29 at the seedling stage; it also demonstrated high resistance to powdery mildew pathogen race E26 at the seedling stage and maintained high resistance against field mixed isolates at the adult-plant stage. Molecular marker analysis confirmed that Yunmai 112 integrated 4 disease resistance genes:powdery mildew resistance genes Pm2 and Pm8, and stripe rust resistance genes Yr9 and YrSP, all of which could amplify specific bands. Molecular cytogenetic analysis revealed that Yunmai 112 carried alien chromatin segments, with GISH signals indicating their origin from the rye genome. Subsequent FISH karyotyping confirmed that this translocation fragment was at the tip of the 1R short arm. the terminal segment substitution of rye 1RS for wheat 1BS, belonging to the 1RS-1BS/1BL wheat-rye small fragment translocation line. 【Conclusion】The new wheat variety Yunmai 112 is highly resistant to powdery mildew and stripe rust. This wheat variety belongs to the 1RS-1BS/1BL wheat-rye small fragment translocation line, which integrates 2 powdery mildew resistance genes, Pm2 and Pm8, as well as 2 stripe rust resistance genes, Yr9 and YrSP.