Gliadins and high-molecular-weight glutenin subunits variation in Aegilops searsii.

Aegilops searsii is a diploid , autogamous annual grass of the Sitopsis section of the genus Aegilops and, according to Feldman (1978), it could be considered as the B genome donor to cultivated wheats. The study of seed storage proteins from numerous .Ae.searsii accessions, using electrophoretical and RP-HPLC techniques, suggests that this species contains similar gliadin components and has a similar HMW glutenin subunit distribution to those coded by genes located on the chromosomes of the wheat B genome. The electrophoretic results also show that it is characterized by the presence of novel gliadin components and HMW glutenin subunits in comparison with cultivated wheat. Ae. searsii, because of its relationship with cultivated wheats and its additional protein components not found in wheat, could be a powerful source for wheat quality improvement. The production of Chinese Spring-Ae. searsii disomic addition lines (Pietro et al., 1983) makes it possible in this species to allocate gliadin and glutenin genes to specific chromosomes. This, along with the study of protein variation, might help in establishing phyletic relationships with cultivated wheats.