Cereals & Grains Association
Log In

Improving wheat milling and baking quality via development of novel Puroindoline alleles.
J. D. KAMMERAAD (1), J. M. Martin (1), S. Cuesta (2), A. Hogg (1), M. Giroux (1). (1) Montana State University, Bozeman, MT, U.S.A.; (2) University of Córdoba, Córdoba, Spain

Wheat (<i>Triticum aestivum</i>) grain hardness is an important factor in determining both end-product quality and milling properties.  Grain hardness in hexaploid wheat is determined by the <i>Hardness </i>locus which consists of the tightly linked puroindoline genes, <i>pina-D1a </i>and <i>pinb-D1a. </i> Hard wheats possess a mutation in either <i>pin </i>gene with the vast majority possessing one of two common mutations, either p<i>ina-D1b</i> or <i>pinb-D1b</i>.  We previously demonstrated the creation of more than 50 new <i>pin</i> alleles via ethyl methanesulfonate mutagenesis which conferred varying levels of grain hardness.  In this study the degree to which individual<i> pina</i> or<i> pinb</i> alleles modify PINA or PINB function will be examined and to what extent they impact end product quality.  A set of five new<i> pina</i> and five new<i> pinb</i> alleles were characterized and the impact each mutation has upon PINA and PINB levels in seeds and present on starch granules was determined.  The amount of PINA and PINB present on starch is a measure of the relative function of PIN.  The preliminary results indicate a close relationship between grain hardness and PINA/PINB starch bound levels.  At least one new <i>pin</i> allele may represent a gain in PIN function since its levels on starch were significantly increased and grain hardness was decreased.  Since PINs bind to membrane polar lipids on the surface of starch granules we have begun to examine the extent to which PIN function is linked to seed polar lipid levels.  As with grain hardness and the amount of PINs bound to starch, the level of polar lipids in seeds likely closely tracks that of PIN function.  Experiments to examine the extent to which each of these new alleles impacts wheat end product quality are underway with the largest impact expected to occur in milling properties.  

View Presentation