Abstract:

【Objective】 This research aims to develop a TRAP marker that is closely linked to or co-segregated with Lr24, and could be employed as a probe for library screening. 【Method】 TRAP analysis was employed and ninety TRAP primer pairs were used to test the resistant and susceptible parents, as well as the resistant bulk (Br) and the susceptible bulk (Bs) in this study. The TRAP primers displaying polymorphism between tested lines were employed to map the linkage in the F2 population derived from TcLr24×Thatcher subsequently, and to detect the specificity of the primer with 45 NILs of wheat leaf rust resistance and 30 diploid materials of wheat further. 【Result】 Ten of 90 TRAP primer pairs displayed polymorphism among TcLr24, Br and Thatcher, Bs, accounting for 11.11%. And a further study found that one stable primer, ARBI1/ RGA-2F, generating a 161 bp fragment was presented only in F2 resistance population, and absent in susceptible population. Forty-five wheat leaf rust resistance NILs or single gene lines and 30 diploid materials of wheat were also tested with this primer pair. This specific band was also present in TcLr19, TcLr29, TcLr38, Lr42 and TcLr44, but absent in all the 30 diploid materials. 【Conclusion】 It is concluded that the marker ARBI1/ RGA-2F is closely linked to Lr24, and can be used for MAS to detect Lr24 in Lr24 resistance breeding, further can be used as a probe for screening cDNA and BAC library of TcLr24.

Key words: wheat leaf rust, resistance genes, TRAP, Lr24