Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2017
Publication Date: 4/25/2017
Publication URL: http://handle.nal.usda.gov/10113/5678149
Citation: Ibba, M., Kiszonas, A., Morris, C.F. 2017. Evidence of intralocus recombination at the Glu-3 loci in bread wheat (Triticum aestivum L.). Theoretical and Applied Genetics. 130:891-902.
Interpretive Summary: Bread wheat is one of the most cultivated crops across the world and one of the major source of proteins in the human diet. Its application into a wide range of daily products is mainly determined by prolamins, a group of seed storage proteins that confers the typical viscoelastic properties to wheat dough. The aim of this paper is to elucidate the genetic linkage present between different genes encoding for the low-molecular weight glutenin subunits, one of the major components of wheat seed storage proteins with a critical role in the determination of wheat flour bread-making quality.
Technical Abstract: The low-molecular weight glutenin subunits (LMW-GSs) are one of the major components of wheat seed storage proteins and play a critical role in the determination of wheat flour bread-making quality. The genes encoding for this class of proteins are mainly located at the orthologous Glu-3 loci (Glu-A3, Glu-B3 and Glu-D3), on the short arm homeologous group 1 chromosome. However, due to the complexity of these chromosomal regions and the high sequence similarity between different LMW-GS genes, their genetic organization and recombination characteristics are still poorly understood. The aim of this study is to provide evidence of the presence of intralocus recombination at the Glu-3 loci in two bread wheat recombinant inbred lines (RILs) populations and one double haploid (DH) population, all segregating for the Glu-A3, Glu-B3 and Glu-D3 loci. The analysis was conducted by using a LMW-GS gene marker system that consists in the amplification of the complete set of the LMW-GS genes and their successive visualization by capillary electrophoresis. Recombinant LMW-GS gene profiles were detected in both the DH and the two RIL populations with different recombination rates depending on the locus and the population. No recombination was present between the i-type and the s-type LMW-GS genes located respectively at the Glu-A3 and Glu-B3 loci, indicating the tight linkage between these genes. Results of this study will help to elucidate the genetic linkage present between different LMW-GS genes and to develop more specific molecular markers that better represent the genetic diversity of these loci.