Storage-protein variation in wild emmer wheat ( Triticum turgidum ssp. dicoccoides) from Jordan and Turkey. I. Electrophoretic characterization of genotypes.

Seed storage-protein variation at the Glu-A1, Glu-B1 and Gli-B1/Glu-B3 loci in the tetraploid wild progenitor of wheat, T. dicoccoides, was studied electrophoretically in 315 individuals representing nine populations from Jordan and three from Turkey. A total of 44 different HMW-glutenin patterns were identified, resulting from the combination of 15 alleles in the A genome and 19 in the B genome. Twenty-seven new allelic variants, 12 at the Glu-A1 locus and 15 at the Glu-B1 locus, were identified by comparing the mobilities of their subunits to those previously found in bread and durum wheats. The novel variants include six alleles at the Glu-A1 locus showing both x and y subunits. The genes coding for the 1Bx and 1By subunits showed no or very little (3%) inactivity, the 1Ax gene showed a moderate degree (6.3%) of inactivity whereas the gene coding for lAy showed the highest degree of inactivity (84.8%). A high level of polymorphism was also present for the omega- and gamma-gliadins and LMW-glutenin subunits encoded by genes at the linked Gli-B1 and Glu-B3 loci (19 alleles). Some Jordanian accessions were found to contain omega-gliadin 35, gamma-gliadin 45, and LMW-2 also present in cultivated durum wheats and related to good gluten viscoelasticity. The newly-discovered alleles enhance the genetic variability available for improving the technological quality of wheats. Additionally some of them may facilitate basic research on the relationship between industrial properties and the number and functionality of HMW- and LMW-glutenin subunits. [ABSTRACT FROM AUTHOR]