The intrachromosomal mapping of a glucose phosphate isomerase structural gene, using allelic variation among stocks of Chinese Spring wheat

SUMMARY Detectable allelic variation at theGpi-1loci on the short arms of the homoeologous group 1 chromsomes in wheat is not common. However, a variant null allele at theGpi-D1locus is present in some stocks of Chinese Spring. This has allowed the locus to be mapped between the ω-gliadin locus carried distally on the short arm of chromosome 1D,Gli-D1(34·5%) and the high-molecular-weight glutenin subunit locus carried near the centromere on the long arm,Glu-D1(36·2%). The origin of this isoenzyme polymorphism in Chinese Spring stocks is described and its potential significance is discussed in relation to quantitative analysis of aneuploids, alien chromosome addition and substitution lines and intervarietal chromosome substitution lines involving Chinese Spring.