Identification of Western U.S. wheat varieties by polyacrylamide gel electrophoresis of gliadin proteins

Abstract

Polyacrylamide gel electrophoresis (PAGE) patterns of gliadin endosperm proteins were obtained for 52 western U.S. wheat varieties, using foundation seed stocks or stocks maintained by wheat breeders. Two PAGE procedures were used; one, based on a uniform concentration of Polyacrylamide, was somewhat superior in the number of bands separated; the other, based on a Polyacrylamide concentration gradient, required much less time. Their combined use appeared advantageous, although patterns obtained by either method could be used to distinguish and identify most of the varieties examined. Exceptions were the pairs Gaines and Nugaines, Manning and Hansel, Fielder and Fieldwin, Hatton and McCall, and possibly, Cajeme 71 and Yecora Rojo. More than one pattern among individual seeds within a variety sample indicated two or more biotypes (genetic variants) in 17 of the varieties. These variations ranged from the occurrence of about equal numbers of two quite different patterns to the occurrence of one predominant pattern with biotypes of slightly different patterns in minor proportions. The presence of biotypes in some varieties complicates the determination of the varietal composition of wheat samples, but at present, no other techniques are available that approach the resolution given by PAGE for the purpose. Photographs of the gliadin patterns included in this report can serve as reference documentation for future work on gliadin proteins in western U.S. wheats.