Submitted to: International Wheat Quality Conference
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2005
Publication Date: 10/5/2005
Citation: Graybosch, R.A. 2005. Development and characterization of waxy winter wheats. International Wheat Quality Conference 113-122. Interpretive Summary:
Technical Abstract: Waxy grain crops produce endosperm starch lacking amylose and consisting only of amylopectin. Such starch is formed when mutations are present that eliminate the production, or function, of an enzyme known as the granule-bound starch synthase, (GBSS, or the “waxy protein”). Waxy winter wheats were developed via development of procedures that allowed separation of the gene products (GBSS isoforms) of the three hexaploid wheat waxy (Wx) loci, identification of adapted and un-adapted lines carrying the three null or non-functional mutations, intermating of such lines to derive waxy progeny, and a multi-cycle process of crossing and backcrossing to transfer the waxy trait to superior genetic backgrounds. The waxy trait now has been introduced to a number of hard and soft winter wheat genetic backgrounds. Grain yields of waxy winter wheats in Great Plains environments now equal those of many currently grown wheat cultivars, suggesting no yield penalty is associated with the trait. Starch produced by waxy wheats is identical in size and shape to that of typical (wild-type) and partial waxy (one or two null muations present) wheat lines, but differs in a host of biophysical and functional properties. Gluten strength is independent of the waxy trait, but flour water absorption properties are markedly altered. Waxy wheat flour has been tested in a variety of products including bread, tortillas and wet noodles. Results suggest that blends of waxy and wild-type flours can impart significant improvement in product performance.