HIGH M(R) GLUTENIN SUBUNITS OF INDIAN WHEAT CULTIVARS - ASSOCIATION OF SUBUNITS-5-1RS WHEAT-RYE TRANSLOCATION(10 WITH THE 1BL)

The seed proteins of lid commercially-released Indian wheat cultivars were fractionated using sodium dodecyl sulphate polyacrylamide gel ele ctrophoresis (SDS-PAGE) to determine their high M(r) glutenin subunit compositions. Amongst the cultivars, three alleles were identified for the Glu-Al locus (subunits 1, 2 and the null phenotype), eight allel es for the Glu-Bl locus (7, 7+8, 7+9, 6+8, 20, 13+16, 17+18 and a new allele) and two for the Glu-Dl locus (2+12 and 5+10). Nine of the cult ivars were heterogeneous and possessed two or more 'biotypes' with res pect to high M(r) subunits. The cultivars were also analysed for the p resence of the IBL/IRS wheat-rye translocation by SDS-PAGE of unreduce d prolamins and hybridisation of DNA dot blots with a rye-telomere spe cific repetitive DNA probe, pAW-161. Both methods revealed that the ma jority of newly-released Indian wheat cultivars carry this translocati on, thus confirming the agronomic superiority of these lines. While mo st of the normal wheat cultivars possessed high M(r) subunits 2+12, 14 of the 18 translocation cultivars had the allelic subunits 5+10, even though no selection was made for these subunits during the breeding p rocess. This suggests that the subunits 5+10 may play a compensating r ole for the loss of dough strength associated with the IBL/IRS translo cation.