1. Department of Plant Sciences, North Dakota State University, Fargo, ND 58105.
2. USDA-ARS, Wheat Quality Lab, Harris Hall, North Dakota State University, Fargo, ND, 58105. Mention of firm names or trade product does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.
3. Corresponding author. Phone: 701-231-8069. E-mail: Douglas.Doehlert@ndsu.nodak.edu