|Graybosch, Robert - Bob|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2004
Publication Date: 11/20/2004
Citation: Graybosch, R.A., Baenziger, P.S. 2004. Registration of three partial waxy winter wheats. Crop Science 44: 2273-2274. Interpretive Summary: Healthy rural economies are dependent upon stable markets for the produce of American farms, and U.S. wheat producers face increasingly stiff competition in world export markets. Traditional uses of bread or common wheat largely have been restricted to the production of leavened bakery products. One means of strengthening rural economies would be the expansion of possible uses of bread wheats, with a concomitant increase in market demand for wheat grain. One possibility is to develop wheats for use in Asian noodle markets. Traditional uses of bread wheats generally were dependent upon the development of wheats with adequate protein content and quality. However, application in some noodle markets is dependent upon the production of wheats with acceptable starch characteristics, which in turn, contribute acceptable noodle cooking texture. Wheat breeders can develop such wheats, but require the necessary genes for novel starches to be present in useful genetic backgrounds. The three partial waxy winter wheats developed by USDA-ARS allow wheat breeders access to two genes that can contribute to optimal noodle quality. These genes have been placed, via traditional plant breeding, in useful winter wheat backgrounds. These wheats can serve as donors of the desired traits, but will not contribute additional other negative effects that would slow breeding progress. The genes for the partial waxy trait are naturally occurring mutations, and were not the product of any sort of biotechnology.
Technical Abstract: This paper describes the release of three partial (reduced amylose) waxy wheat germplasm lines: PI 617069 (96MD7413-58), PI 617070 (96MD7413-36) and PI 617071 (96MD7110-71). These partial waxy wheats carry non-functional (null) alleles (Wx-A1b, and Wx-B1b) at two of the three hexaploid wheat Wx loci. These loci encode isoforms of the enzyme granule-bound starch synthase (GBSS, EC 184.108.40.206), also is known as the 'waxy' protein. Wheats with non-functional alleles at two loci are known as 'double-nulls'. Double-null partial waxy wheats produce endosperm starch with reduced amylose content, relative to that of single-null or wild-type wheats. Such starch confers unique functional properties to derived wheat flour. Suggested uses for partial waxy wheats include as a novel source for the production of modified food starches, and as a blending agent to create flours with optimal amylose concentration for the production of a variety of sheeted and baked food. Partial waxy wheats also are useful as donors of the Wx null alleles for the breeding of completely waxy (amylose-free, triple-null) lines. Crosses between double-null partial waxy wheats and completely waxy wheats will result in populations composed of 25% waxy individuals. In comparison, populations derived from crosses between wild-type wheat and waxy wheat will produce waxy progeny at a frequency of only 1/64.