Variation in LMW- glutenin subunits was studied in 67 bread wheat varieties. The glutenin and gliadin proteins were extracted through sequential extraction procedure. One - step 1- dimensional SDS-PAGE with 8.1-12.5% gradient gel was used for separation of glutenin & gliadin in subunits. Seventeen Glu-I subunits and 19 Glu-3 subunits were recognized. A new subunit in Glu-1 (2**+10*) was observed in 4 of the varieties, 7(a) and lO(i) subunits were seen independently in 2 varieties, however, 1 By and 1Dx were not expressed. In Glu-1, the 2+12(a), 7+8(b) and null (c) had the highest frequencies of 0.71, 0.64 and 0.56, respectively. Glu-A3c, Glu-B3b and Glu-D3b in Glu-3 constituted the most frequent subunits, with 0.4, 0.25 and 0.35 relative frequencies respectively. Compared to Glu-1, the variation in each locus and also the overall mean variation of Glu-3 were higher. co- gliadins showed higher variation than total variation Glu-1 or Glu-3 subunits, but lower than total variation Glu-1 and Glu-3. The maximum variation being observed, when the Glu-I, Glu-3 and co-gliadin were taken into consideration together. Only varieties Alamoot 1 and Alamoot 2 were similar at HMW, LMW and co-gliadin loci, the results indicated the following order of variation in different loci.
coGli & Glu-3 & Glu-l> Glu-3 & Glu-l> coGli>Glu-3>Glu-1.
)