IDENTIFICATION OF CULTIVARS OF CROP SPECIES BY POLYACRYLAMIDE ELECTROPHORESIS .1. COMMERCIAL BARLEY (HORDEUM-VULGARE L) CULTIVARS GROWN IN GERMANY

Hordein electropherograms of single seeds extracted with (i) 55% (v/v) isopropanol and 0.1% dithiothreitol and (ii) 30% (v/v) chloroethanol, analysed by acidic polyacrylamide electrophoresis (A-PAGE) employing pre-dried, ready made gels and electrophoretic kits (Pharmacia Biotechnology, Freiburg) were used to differentiate 95 commercial spring barley and 72 winter barley cultivars grown in Germany. The polymorphism exhibited by isopropanol extracted seeds (pH 4.3) at three hordein regions corresponding to proteins with the least mobility, intermediate mobility and rapid mobility, enabled 80% of spring barley, 30% of six-rowed and 50% of two-rowed winter barley to be classified respectively. Further analyses with chloroethanol extracted seeds at pH 4.3 and 5.5 resulted in the differentiation of all spring cultivars and 90% of the winter cultivars. With the exception of one protein band which is not used as a criterion for differentiation, single seed and malt extracts gave identical band patterns. Advantages of the present method of analyses include improved resolution of banding patterns, rapid identification of cultivars by means of seed and malt extracts and the ease of handling and differentiation of a large number of samples effectively.