小麦抗叶锈病基因Lr24的TRAP分析

Studies on Gene Lr24 Conferring Resistance to Wheat Leaf Rust by TRAP Analysis

【目的】获得与Lr24基因紧密连锁并可能作为探针的TRAP分子标记。【方法】应用TRAP技术,选用90对引物组合对小麦抗叶锈病基因Lr24、感病亲本Thatcher及其F2代抗感各10株组成的抗、感基因池(Br、Bs)的扩增带型差异进行分析,用筛选获得的多态性引物对TcLr24×Thatcher F2群体进一步筛选,进而用获得的特异引物对45个小麦抗叶锈病近等基因系和30个小麦二倍体材料进行分析。【结果】获得10对能够在TcLr24、Br与Thatcher、Bs间产生多态性的引物,多态性引物检出率为11.11%。其中1对在F2抗感群体中有差异且稳定扩增的TRAP引物ARBI1/RGA-2F,其161bp扩增产物仅在F2抗病单株中出现,感病单株中缺失。用该引物对45个近等基因系和30个二倍体材料检测发现,近等基因系TcLr19、TcLr29、TcLr38、Lr42和TcLr44中有相同大小片段的扩增产物,30个二倍体材料中未出现相应扩增产物。【结论】本研究获得的一个与Lr24紧密连锁的TRAP标记,该标记可筛选含有Lr24基因的育种后代群体,可作为探针用于文库的筛选。

[ 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 TcLr24xThatcher 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 TcLrl9, 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.