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Total proteins were extracted from degermed seeds of various species of Triticum and Aegilops with solutions containing sodium dodecyl sulfate (SDS) and mercaptoethanol. The reduced, dissociated proteins were fractionated according to molecular weight (MW) by high-resolution polyacrylamide gel electrophoresis in buffers containing SDS (SDS-PAGE). Stained SDS-PAGE patterns were measured by densitometric scanning over a suitable range of optical density. The data were normalized to equivalent total areas for each of the densitometric scans by means of a computer program that also permitted the construction of patterns of hypothetical amphiploids by averaging patterns of two or three diploid species. The grain proteins of most species examined had distinctive qualitative and quantitative aspects that were characteristic of the species even though nearly every accession or cultivar of a species exhibited at least minor differences in pattern from other accessions or cultivars. The main protein components (probably prolamins) of Triticum monococcum ssp. monococcum, T. monococcum ssp. boeoticum, T. urartu, and Aegilops squarrosa had MW's in the range 29-36 X 10(3) whereas the most important components of Ae. speltoides, Ae. longissima, and Ae. searsii had MW's in the range 37-55 × 10(3). Changes in the quantitative expression of particular genes, especially those coding for storage protein components, may have been associated with speciation. The strong predominance of proteins with MW's in the range 29-36 × 10(3) in some accessions of AB genome tetraploids, such as T. turgidum ssp. dicoccoides, may indicate contributions to the B genome of these tetraploids by T. monococcum ssp. boeoticum, T. urartu, or Ae. squarrosa.

Buffers containing sodium dodecyl sulphate (SDS) and mercaptoethanol (ME) were used to extract total protein from the flour or single seeds of five different wheat (Trriricum aesfirwm L.) varieties (Scout 66, Red River 68, Bankuti 1201, Atlas 66, and Omar). A dye-binding analysis for protein was adapted to these extracts. The extracted proteins were separated according to molecular weight (mol. wt) by gel electrophoresis with SDS and the patterns were quantitated by densitometry of the gels, after proteins had been stained with Coomassie brilliant blue R250. The patterns were divided into five different areas corresponding to mol. wt ranges of 63 x lo3 and greater (Al), 48-63 x 103 (A2), 40-48 x lo3 (A3), 31-40 x lo3 (A4), and 8-31 x lo3 (A5).The proportions of the total area corresponding to these subareas were compared for the different varieties. Dye absorption was assumed to be directly proportional to protein concentration (in the linear range) with the same proportionality holding for the first four areas (largely storage proteins). The proteins of AS (largely albumins) were assumed to have a three-fold greater dye-binding capacity than the other proteins and a correction to this area was based on this assumption. Red River 68, a variety with strong mixing characteristics, had a comparatively large proportion of its total protein in A3 and a notable peak of mol. wt 46 x lo3 in this area. Bankuti 1201 and Omar, with weak mixing characteristics, had comparatively small proportions of their protein in A3, but large proportions in A4 (largely gliadins). Atlas 66 had a comparatively large proportion of its protein in AS (largely albumins) and a smaller proportion in A4, but there were no strong differences in the pattern that could be related clearly to the high-protein character of Atlas 66. All the varieties had most of their protein (65-69%) in the mol. wt ranges corresponding to A3 and A4.

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