Bread wheat lines with both x- and y-type subunits at the Glu-A 1 locus

Reversed phase high performance liquid chromatographic (RP-HPLC) separations of high Mr glutenin subunits present in two Swedish breeding lines, which have been reported to possess a novel subunit at the Glu-A 1 locus, showed the presence of an additional peak whose behaviour is similar to y-type subunits encoded by genes at the Glu-A 1y locus and present only in wild wheats T. urartu (AA) or T. dicoccoides (AABB). Based on biochemical analyses and on the tight linkage observed with subunit 21 *, it is suggested that the additional component (indicateci as 21 *y), present in the breeding lines analysed, corresponds to the y-type subunit encoded at the Glu-A 1 locus. Because cultivated polyploid wheats have been shown to have only the x-type subunit at the Glu-A 1 locus it is speculateci that the new combination, with both x- and y-type subunits expressed, might have been introgressed, during breeding processes, from the wild wheat progenitors, T. urartu or T. dicoccoides, which possess genotypes expressing both types of subunits.