engleski

Discrimination of barley varieties by electrophoretic methods

Barley breeders, growers and traders, as well as green malt producers and breweries have a need for reliable and simple methods for discrimination of barley varieties. Among various approaches electrophoretic analysis of barley proteins were recommended. However, according to literature reports only varieties grouping and not their full differentiation were achieved. Therefore it is of interest to search for useful modifications of standard separation methods, as well as for the new differentiation markers. We have examined applicability of various electrophoretic procedures and aminopeptidase isoenzymes detection for differentiation of barley cultivars. Barley Angora, used as a standard, and five domestic cultivars Barun, Rodnik, Sladoran, Rex and Martin were compared. Proteins (albumins/globulins and hordeins) were extracted from barley dry grains and green malt and separated using native PAGE pH 8, 9, SDS-PAGE 10%T Laemmli, SDS-PAGE in gradient gel 8-18% T, IEF in pH gradient 3, 5-9, 5 and pH 5, 5-8, 5. For aminopeptidase isoenzymes detection albumins/globulins were separated by native PAGE pH 8, 9 and IEF pH 4, 0-6, 5, and activities of aminopeptidases were tested in gel slices using 2-naphthylamides of amino acids phenylalanine, leucine and arginine. It was shown that analysis of dry grain extracts gave better results than analysis of green malt extracts. In all separation experiments the Angora barley could be distinguished from the domestic varieties. By standard electrophoretic procedures domestic cultivars could be grouped as follows: Rodnik/Sladoran, Barun/Rex, and Martin. All five varieties could be distinguished by analysis of hordeins using SDS PAGE in gradient gel 8-18% T and IEF in pH gradient 5, 5-8, 5, combined with densitometric quantification. Aminopeptidase isoenzymes were not found as applicable markers for discrimination of the examined barley cultivars.

barley; electrophoretic separation; aminopeptidase isoenzyme detection

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