Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2003
Publication Date: 9/28/2003
Citation: Bean, S., Dixon, C.E., Tuinstra, M., Pedersen, J., Erpelding, J. 2003. Relationships between endosperm protein composition and grain hardness in sorghum. Paper No. 264. Page 123 in: Program Book of the 88th AACC Annual Meeting. Abstract. Interpretive Summary: Abstract for AACC Meeting that is being held Sept. 28 through Oct. 2, 2003 in Portland, OR.
Technical Abstract: Physical grain attributes, such as hardness, can be an important end-use quality determinant. Grain hardness in sorghum has been linked to quality traits such as abrasive milling quality, plant defense, and food quality. However, the biochemical basis for grain hardness in sorghum is still not well understood. Thus, the goal of this study was to investigate the relationships between grain hardness index (HI) by single kernel characterization system (SKCS), abrasive hardness index (AHI), and endosperm protein composition in sorghum. Sorghum samples varying in hardness values were decorticated, and floury and corneous endosperm were separated using a dremel motor tool. Protein content and composition (using RP-HPLC and HPCE) were measured on endosperm and isolated endosperm fractions. Total protein contents were not significantly correlated with SKCS-HI values, but highly related to AHI values (r=0.80). Likewise, corneous protein contents were not significantly correlated with SKCS-HI values but were correlated to AHI (r=0.75). Floury endosperm protein contents were correlated to neither SKCS-HI nor AHI values. The ratios of soft to hard endosperm were strongly correlated to both SKCS-HI and AHI values, except for one sorghum line with unusually large grains and a substantially different shape than typical sorghum grains.