Genetic control of α-Amylase production in wheat.

An analysis of the α-amylase isozymes in GA-treated endosperm of wheat nullisomic-tetrasomics shows that there is more variation at the α-Amy-1 and α-Amy-2 homoeoallelic loci than was previously thought. Among the 16 isozymes produced by genes on the group 7 chromosomes, most could be definitely established as products of a single homoeoallele.Inter-varietal allelic differences would be expected at such loci and clear variation was found in isozymes produced by chromosomes 6B and 7B. The latter allele, α-Amy-B2b carried by the variety 'Hope', was used to locate the enzyme structural gene within chromosome 7B relative to the centromere and five other gene markers.The nature of the α-Amy-B2b phenotype and the rare non-parental isozyme patterns found among the recombinant lines indicates that the locus is large and compound, probably involving some degree of intra-locus gene duplication.