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Discussion

HMW secalins are related structurally to the HMW prolamins in wheat and barley (Shewry et al 1984b). HMW prolamins (glutenin) subunits of wheat are coded at each locus on the long arms of homoeologous group1 chromosomes (Payne et al 1982). Each locus contained two HMW subunit genes, whose intra-locus recombination occurred very infrequently at
Glu-B1 locus being 0.11 + or - 0.07cM and not observed at Glu-D1 locus (Payne et al 1983).

Based on these facts, it can be assumed that there are two Sec 3 loci at a distance of recombination value 7-11% on the long arm of chromosome 1R and each locus consists of one or two genes as shown in
Fig. 2. These assumptions are supported strongly by the facts that number of HMW secalin bands is larger than those of wheat per genome and variation in the staining intensity of the same bands is observed in the F2 populations and among inbred lines in our experiments.


References

Payne PI, Law CN and Mudd EE (1980) Control by homoeologous group 1 chromosomes of the high-molecular-weight subunits of glutenin, a major protein of wheat endosperm. Theor Appl Genet 58: 113-120.

Payne PI, Holt LM, Worland AJ and Law CN (1982) Structural and genetical studies on the high-molecular-weight subunits of wheat glutenin. Part 3. Theor Appl Genet 63: 129-138.

Payne PI, Holt LM, Thompson RD, Bartels D, Harberd NP, Harris PA and Law CN (1983) The highmolecular-weight subunits of glutenin: classical genetics, molecular genetics and the relationship to bread-making quality. Proc 6th Int Wheat Genet Symp 827-834.

Shewry PR, Bradberry D, Franklin J and White RP (1984a) The chromosomal locations and linkage relationships of the structural genes for the prolamin storage proteins (secalins) of rye. Theor Appl Genet 69: 63-69.

Shewry PR, Miflin BJ and Kasarda DD (1984b) The structural and evolutionary relationships of the prolamin storage proteins of barley, rye and wheat. Philos Trans R Soc London B 304: 297-308.

Shewry PR and Miller TE (1985) The genetics of rye seed proteins. Eucarpia Meeting of the Cereal Section on Rye: 617-627.

Singh NK and Shepherd KW (1984) Mapping of the genes controlling high-molecular-weight glutelin subunits of rye on the long arm of chromosome 1R. Genet Res 44: 117-123.

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