Fast identification of wheat 1BL.1RS translocation by reversed-phase ultra-performance liquid chromatography (RP-UPLC)

The 1BL.1RS chromosomal translocation in wheat is the result of replacement of the short arm of chromosome 1B of wheat by the short arm of chromosome 1R of rye, which had been widely used as a parental line in worldwide wheat breeding, resulting in a high percentage of wheat cultivars containing this translocation. A fast and reliable approach to identify this translocation is highly desirable in modern wheat breeding. This study compared reversed-phase ultra-performance liquid chromatography (RP-UPLC), acidic polyacrylamide gel electrophoresis (A-PAGE), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), allelic-specific PCR, and reversed-phase high-performance liquid chromatography (RP-HPLC) approaches to identify the 1BL.1RS translocation in 76 bread wheat cultivars. Two gliadin bands in the Gli-B1 region of A-PAGE separation were confirmed by LC-MS/MS to be omega secalins from the 1BL.1RS translocation, and they can be used as reliable protein markers for identifying the translocation. A few specific minor peaks eluted at 12-13min on the RP-UPLC patterns can readily differentiate the 1BL.1RS translocation. Of the 76 wheat cultivars tested, 40 were identified as carrying the 1BL.1RS translocation by RP-UPLC, which was consistent with the results of A-PAGE, HPLC, and PCR. Compared with other established methods, RP-UPLC showed a clear advantage in fast identification of the 1BL.1RS translocation with higher reliability and lower costs, and it is therefore ideal for large-scale screening of the 1BL.1RS translocation in wheat breeding.