IDENTIFICATION OF REPRODUCIBLE PCR-RAPD MARKERS THAT ENABLE THE DIFFERENTIATION OF CLOSELY-RELATED 6-ROWED MALTING BARLEY (HORDEUM-VULGARE L) CULTIVARS

Varietal purity of barley seed and malt lots is important to the malti ng and brewing industries. This study was conducted to see if a modifi ed polymerase chain reaction (PCR) technique using random DNA primers (PCR-RAPD) could generate repeatable polymorphisms among the closely r elated six-rowed malting cultivars Morex, Robust, Stander, Excel, and elite breeding line M77. From a total of 80, 30 random 10-mer primers were selected based on their ability to generate reproducible polymorp hisms between the cultivars Steptoe and Morex. Bulked DNA isolated fro m the leaves of 10-12 plants of each cultivar was amplified using the Stoffel fragment of recombinant Thermus aquaticus DNA polymerase and o ne primer per PCR. Nine of the 30 primers detected repeatable polymorp hisms among the malting lines. Each cultivar or line could be distingu ished from another with the exception of Stander and M77. The results of six primers were reproduced in a second laboratory. It was conclude d that this PCR-RAPD technique could be useful for distinguishing the four six-rowed malting barley cultivars. A faster version of the techn ique may be required for practical cultivar identification by the barl ey processing industry.