Characterization of HMW Glutenin Subunits in Thinopyrum intermedium, Th. bessarabicum, Lophopyrum elongatum, Aegilops markgrafii, and Their Addition Lines in Wheat

High molecular weight (HMW) glutenin subunits (GSs) play an important role in determining end-use quality in wheat (Triticum aestivum L.). They are also excellent protein markers for genotype identification. In this study, we analyzed the HMW-GSs in Thinopyrum bessarabicum (Savul. and Rayss) A. Love, Th. intermedium (Host) Barkworth and D. R. Dewey, Lophopyrum elongatum (Host) A. Love, and A. markgrafii (Greuter) Hammer and genotyped eight sets of 44 disomic addition lines derived from these species in common wheat or durum wheat background using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and urea/SDS-PAGE. A total of 20 unique alleles for HMW-GSs were identified from the alien species. Among the eight sets of addition lines, only four addition lines carried the HMW-GSs derived from alien species. In the wheat-Th. intermedium chromosome 1Ai addition line TA3649, the HMW-GSs encoded by Glu-D1 were not expressed while the alien HMW-GSs were present, indicating that the Glu-D1 locus might be lost or the alien chromosomes might have silenced the expression of the Glu-D1 alleles. The wheat-Th. intermedium chromosome 7Ai long arm ditelosomic addition line, TA3659, carried two sets of HMW-GSs (1Dx4+1Dy12 and 1Dx5+1Dy10) encoded by the Glu-D1 locus. The results in this study also provided information on the alien chromosome donors and wheat parents for some disomic addition lines. Such information is useful for the development of molecular markers that will facilitate the introgression of desirable genes from the alien chromosomes into wheat genomes. The identified novel HMW-GS alleles may serve as new genetic resources for wheat quality improvement.