A highly leaf rust resistant genetic stock 19HRWSN-76 from CIMMYT was crossed to a susceptible variety Zhengzhou 5389 to generate F 1 and F 2 population to find out the mode of inheritance and map the resistance gene. The F 2 population was inoculated with uredosporic inoculum of physiological race FHJP of leaf rust. The 3:1 ratio of resistant and susceptible plants in F 2 suggested that the leaf rust resistance in 19HRWSN-76 is controlled by a single gene, tentatively named Lr19HRWSN-76. Relationship between the known leaf rust resistance gene Lr24 and Lr19HRWSN-76 located on chromosome 3D was established by SSR marker barc71 and STS 24-16.

The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to all pathotypes tested. F 1 and F 2 plants from the cross Yu 356-9 (resistant)/Zhengzhou 5389 (susceptible) were tested with leaf rust pathotype "FHNQ" in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as LrYu. Bulk segregant analysis and molecular marker assays were used to map LrYu. Five SSR markers on chromosome 2BS were found closely linked to LrYu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 cM.