Frequent absence of GBSS 1 B isoprotein in endosperm starch of Canadian wheat cultivars

Granule bound starch synthase 1 (GBSS 1) is an enzyme involved in amylose synthesis, and it is encoded at the waxy loci in wheat. Mutations have been reported for three GBSS 1 loci in wheat. Mutations at wheat GBSS 1 loci result in the absence of GBSS 1 isoproteins with concomitant reduction in the amylose concentrations of endosperm starch. A recent survey of Canadian wheat cultivars detected the frequent absence of GBSS 1 B isoprotein in endosperm starch granules. This was likely a result of many Canadian spring wheat cultivars having common parents, which have a mutation at the GBSS 1 B locus.