Differentiation of Croatian Barley Varieties by Gradient Gel Sds-page and Isoelectric Focusing of Dry Grains and Green Malt Hordeins

Barley malting and brewing processing properties, as well as potential grain yield, morphology, physiological traits, and resistance to certain fungi and viral diseases are cultivar dependent. Therefore, reliable and simple method for variety recognition is of a great importance for the malting and brewing industries, as well as for barley breeders, growers and traders. Among various approaches, analysis of barley grain storage proteins, hordeins, by polyacrylamide gel electrophoresis at acidic pH or by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was recommended in year 1988 as the official method for barley variety discrimination (Cooke, 1995; Wrigley, 1995). However, according to the reports in the literature, hordein patterns obtained by the recommended methods, allow only varieties grouping and not their full differentiation (Cooke, 1995; Wrigley, 1995; White and Cooke, 1992). The main obstacle for discrimination of barley variety hordeins is their similarity, developed for two reasons: (i) the majority of modern barley varieties could be traced back to just a few ancestors making them closely related, and (ii) genes coding for the B and C hordeins are located on the same arm of chromosome 5, thus limiting the possibilities of recombination, and subsequent hordein polymorphism (Weiss et al., 1991). Additionally, the recommended method with applied separation conditions does not have high resolution power.