MAPPING OF MALT ENDOPEPTIDASE, NADH DIAPHORASE AND ESTERASE LOCI ON BARLEY CHROMOSOME-3L

Isoelectric focusing (IEF) and immunoblotting were used to detect gene tic variants of malt endopeptidase (MEP1), an enzyme related to maltin g quality in barley and coded by the CepB locus on barley chromosome 3 (= 3H). A variant was found in a Turkish accession of wild barley (Ho rdeum vulgare ssp. spontaneum). The self progeny of a hybrid between t his accession and the barley cultivar 'Clipper' were analyzed for reco mbination between the CepB locus and other isozyme loci. The estimates of recombination linked the CepB locus to an NADH diaphorase locus (N dh2), which in turn was linked to the seedling esterase complex (Est1, Est2, and Est4) situated near the distal end of the long arm of chrom osome 3. The Ndh2 locus was independent of two other NADH dehydrogenas e loci (Ndh3, Ndh5) which were mapped on barley chromosome 5 (= 1H) in relation to the three hordein loci (Hor1, Hor2, and Hor3).