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A collection of 180 Triticum durum lines from Turkey and 22 Italian cultivars were investigated by eiectrophoretic techniques and evaluated for grain parameters such as protein content and sodium dodecyl sulphate (SDS)-sedimentation test. A total of 14 different patterns were observed for high-molecular-weight (HMW) glutenin subunits resulting from the combination of three alleles from the A genome and seven from the B genome. Three new allelic variants, one at Glu-A 1 and two at Glu-Bl, were found. Five different alleles were detected at the Gli-B\ locus. Genotypes with the same allelic variant at Gli-Bl showed inconsistency of composition in B group of low-molecular-weight (LMW) glutenin subunits. A total of 11 different B-subunit patterns were identified in the material analysed. A substantial proportion (78%) of the variation in gluten properties could be explained in terms of protein composition, with the LMW glutenin subunits making the largest contribution (54%). Results indicate that, in addition to Glu-B3 encoded proteins, variation at other loci coding for some intermediate and fastest B subunits might also influence rheological properties.

Sixty hexaploid wheat landraces collected from five regions of Pakistan were assessed for genetic variability in terms of high molecular weight (HMW) glutenin subunits as revealed by SDS-PAGE. The germplasm appeared to be diverse and unique on the basis of HMW glutenin subunit compositions_ Out of 24 alleles detected at all the Glu-1 loci, four belonged to Glu-Al, 12 to Glu-B1 and eight to Glu-D1 locus. The number of novel HMW glutenin subunits detected were 1,4 and 6 at the three loci (Glu-A1, Glu-Bl, Glu-D1), respectively. The frequency distribution patterns of 24 allelic variants detected at the three Glu-1 loci in 1080 samples analysed for 60 accessions were determined both on the basis of individual accessions and on the basis of regions (accessions pooled across the regions). One allele ("null") at the Glu-A1 locus, three alleles (17 + 18, 7 + 8, 14) at the Glu-B1 locus and, two alleles (2 + 12 and 2** + 1U) at the Glu-D1 locus were found most frequently distributed in the 60 populations. Maximum variation was observed in the Baluchistan and Gilgit regions of Pakistan in terms of distribution of novel Glu-1 alleles. A higher gene diversity was observed between the populations as compared to the gene diversity within the populations while, a reverse pattern of gene diversity was observed when populations were pooled across the regions (higher within the regions than between the regions). A data base has been generated in this study which could be expanded and usefully exploited for cultivar development or management of gene bank accessions.

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