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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Publications at this Location » Publication #239981
Title: Sorghum Germplasm Profiling to Assist Breeding and Gene Identification for Biofortification of Grain Mineral and Protein Concentrations

Author
item WATERS, B - University Of Nebraska
item Pedersen, Jeffrey

Submitted to: Plant Nutrition Colloquium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/3/2009
Publication Date: 8/7/2009
Citation: Waters, B.M., Pedersen, J.F. 2009. Sorghum Germplasm Profiling to Assist Breeding and Gene Identification for Biofortification of Grain Mineral and Protein Concentrations. The Proceedings of the International Plant Nutrition Colloquium XVI. Paper 1228.

Interpretive Summary: Sorghum is the world’s fifth most important grain crop, and is a widely consumed staple in subtropical semi-arid regions of Africa and Asia. Increasing the content of mineral micronutrients (especially iron and zinc) and protein is of widespread interest for human nutritional concerns. In this presentation, we report nutritional traits in a set of 95 sorghum lines of wide diversity for concentration of eight minerals (Cu, Fe, K, Mg, Mn, P, S, and Zn), crude protein, and digestibility. The lines were chosen from a set of 2882 lines previously screened for protein concentration. The extreme high protein (10 lines) and low protein (19 lines) lines were selected. Sixty-six additional lines that are also part of a sorghum “diversity panel” were also included. We observed a normal distribution of grain size, digestibility, and mineral concentrations, in most cases with a range of >2-fold. Several minerals showed strong positive correlations with protein concentration, suggesting that mineral and protein density in grain can be improved together. Several minerals were positively correlated, (i.e. Fe and Zn), suggesting that improving accumulation of one of these minerals might also result in increases in others. None of the mineral or protein concentrations were correlated with digestibility. Therefore, sorghum breeders can likely select for improved digestibility independently of mineral or crude protein concentration. Sufficient diversity is present in sorghum germplasm to breed for increased seed mineral and protein. With application of current molecular technologies rapid progress towards development of lines with higher accumulation of nutrients in grain should be possible.

Technical Abstract: Sorghum (Sorghum bicolor) is the world’s fifth most important grain crop, and is a widely consumed staple in subtropical semi-arid regions of Africa and Asia. Biofortification of sorghum by increasing mineral micronutrient (especially iron and zinc) and protein concentration is of widespread interest. Here, we report profiling of a panel of 95 sorghum accessions of wide diversity for concentration of eight minerals (Cu, Fe, K, Mg, Mn, P, S, and Zn), crude protein, and digestibility. Accessions were chosen from a prior large-scale screen for protein concentration (2882 accessions). The extreme high (10 accessions) and low (19 accessions) protein lines were selected, and 66 accessions also included that are in an association mapping panel. We observed a normal distribution of grain size, digestibility, and mineral concentrations, in most cases with a range of >2-fold. Several minerals showed strong positive correlations with protein concentration, suggesting that mineral and protein density in grain can be improved together. Several minerals were positively correlated, (i.e. Fe and Zn), suggesting that improving accumulation of one of these minerals might also result in increases in others. None of the mineral or protein concentrations were correlated with digestibility. Therefore, sorghum breeders can likely select for improved digestibility independently of mineral or crude protein concentration. Sufficient diversity is present in sorghum germplasm to breed for increased seed mineral and protein. Association mapping may allow identification of specific genes that can be used in transgenic approaches to develop lines with higher accumulation of nutrients in grain.