QTL mapping of a high protein digestibility trait in Sorghum bicolor

Jennifer, A.W. and Mason, R.E. and Robbins, A.L. and William, L.R. and Hays, D.B. (2009) QTL mapping of a high protein digestibility trait in Sorghum bicolor. International Journal of Plant Genomics. pp. 1-6.

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Compared with other cereal grains, Sorghum bicolor shows lower protein digestibility. The low digestibility is thought to result from disulfide cross linking in the β- and γ-kafirins. In contrast, the single recessive high digestibility/high lysine content (HD) mutation which confers greater grain digestibility exists in sorghum that is thought to result from reduced accumulation of γ-kafirin that allows greater access to the high digestible α-kafarin fraction. In an effort to both clearly define the molecular basis for the HD trait and develop tools to improve the introgression of this difficult-to-screen trait, this study focuses on mapping the QTLs linked to this trait. While the HD trait has been defined as a single recessive gene, our results uncovered that two major QTLs on chromosome 1 are associated with protein digestibility—one QTL (locus 1 from the HD parent) unfavorably affects digestibility and one QTL (locus 2 from the HD parent) only 20 cM away favorably affects digestibility. A contrast analysis between genotypic groups at these two loci shows that a higher level of protein digestibility may be obtained when this linkage in repulsion is broken and favorable alleles are allowed to recombine

Item Type: Article
Author Affiliation: Department of Soil and Crop Sciences, Institute for Plant Genomics & Biotechnology, Texas A&M University, 2474 TAMU, College Station, TX 77843, USA
Subjects: Crop Improvement
Crop Improvement > Genetics/Genomics
Divisions: Sorghum
Depositing User: Mr T L Gautham
Date Deposited: 14 Apr 2011 05:43
Last Modified: 14 Apr 2011 05:44
Official URL: http://downloads.hindawi.com/journals/ijpg/2009/47...
URI: http://eprints.icrisat.ac.in/id/eprint/1753

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