Capillary electrophoresis of gliadins a tool in the discrimination and characterisation of hulled wheats (T. dicoccon Schrank and T. spelta L.) lines

Twenty-two lines of emmer (T. dicoccon Schrank) and ten of spelt (T. spelta L.) were analysed, using capillary electrophoresis, for their gliadins. These proteins were separated on a 30 cm long (22 cm to detector, 50?m ID) uncoated fused-silica capillary using the isoelectric buffer 40mM aspartic acid, 4M urea, 0.5% (w/v) HEC and 20% (v/v) acetonitrile. Samples were run for 20 min at 22kV and 42°C. By using these conditions, gliadins were separated into 21-30 components (peaks and shoulders). The major peaks eluted between 4.5 and 8.5 min. Electrophoregrams of tested lines showed qualitative and quantitative differences, including number of peaks, presence or absence of some major peaks and areas of peaks. Lines belonging to the same species can be discriminated mainly on the bases of beta- and omega-gliadin patterns. The gamma- and omega-gliadins seems to be more useful in the differentiation of emmer from spelt. The comparison of electrophoregrams relative to hulled and unhulled species evidenced the high similarity between species with the same genome composition (durum wheat/emmer and common wheat/spelt).